JPH01503033A - Overcurrent protection device for power supply of indoor electrical equipment such as houses and factories - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] name of invention Overcurrent protection device for power supply of indoor electrical equipment such as houses and factories Detailed description of the invention The present invention provides a power distribution network according to the generic concept of claim 1 and a phase line of the power distribution network. Branched drop-in wires - The wires in the area of the indoor drop-in area that are connected by wires. each equipped with one overcurrent protection device to protect the Overcurrent protection for indoor electrical equipment in houses and factories, e.g. for power supply of residential power supply equipment Regarding equipment.

A so-called indoor lead-in section is installed as part of a heavy-duty electrical device with a rated voltage of 1000Vy. In order to DIN571 oovDEoi oo series is applied, and this series Other corresponding standards also apply.

In such applications, the indoor drop-in section may be connected to the indoor drop-in line or the indoor drop-in cable; The indoor lead-in part and the indoor lead-in cable are both as follows. Later called lines, such lines start from the entrance to the room and end at The box forms the transition to the current load equipment. Each indoor recess is a retractable box are equipped with the required overcurrent protection devices, and such overcurrent protection devices are often is a band fuse. The minimum cross section for electrical wires in indoor entry points is the overcurrent protection device. It is determined according to the rated voltage surge, and the kotonai draw-in failure is the risk that the wire will cause a fire to the building in the event of an arc short circuit. laid so that it burns without spreading.

In this way, the breaker, which was originally installed for the load equipment, can be used instead of the indoor service line. Even if it is connected to the indoor connection line depending on the case, this breaker is not connected to the load equipment. It operates only when a short circuit or overcurrent occurs inside the device.

When developing construction sites for new housing near large cities or large residential areas, When a new city or district is built, the distribution network for power supply must be expanded accordingly. 9, which was enlarged, and the newly laid si. At present, there are large In a large residential area, various load equipments are connected to different grid voltages in different parts. Not only will the power distribution network with a large number of distribution t#lS buses be expanded, The number of service lines branching from these power distribution grid buses to buildings is also large, especially in residential areas. stomach.

In this case, the drop-in line connected in parallel to the distribution network busbar shall be Similarly, they are laid at a small distance from each other. Expanding the electricity grid to power buildings In the current situation, for example, service lines installed as buried cables are You may be exposed to danger. Shovel-type excavator used for excavation work It is also frequently used during the repair of underground conduits and when laying cables. The jacket of the indoor drop-in cable may be damaged or broken by the civil engineering tools used. As a result, the patch may be shorted. Cable fires that occur in this way or To prevent large fires caused by arc short circuits, the power grid busbars are shorted and The supply of buildings connected to the distribution bus A is interrupted.

For example, damage to the roof of a building caused by lightning, strong winds, heat caused by a building fire, etc. Service lines in the power grid may also be at risk. Especially damage and destruction of service lines Exceptional causes include damage and destruction from buildings, streets, and sidewalks caused by human labor. .

According to the invention, an overcurrent protection device of the type mentioned at the outset, in particular for residential power supply equipment, is provided. This overcurrent protection device is for service lines and also for distribution network busbars. It is controlled by a circuit breaker which is also used for overcurrent equipment in the distribution network and in the service area. It acts quickly when an overcurrent or short circuit occurs in the area between the equipment and the equipment.

The gist of the invention is to additionally provide one overcurrent protection device if' for each of the service lines. - provided in the ILIJ immediately after the branch point of the drop-in line from the power distribution network, The overcurrent protection device includes a breaker, a control unit that operates the breaker, and all other devices. Prepared, The control unit has a signal amplifier powered by current from the electrical grid; Further, if an overcurrent occurs in the lead-in wire -t@ of the lead-in wire, the control unit 1. Supply a signal to the circuit breaker to control the interruption of the current (load current) by the breaker. Equipped with an overcurrent detector, Furthermore, when the cause of the overcurrent is removed, the control unit receives current from the breaker. A monitoring device is provided for supplying a signal for controlling the re-connection of the device.

In this way, an overcurrent protection device with a switchable protection device is realized, This overcurrent protection device is controlled by overcurrent and is designed to prevent overcurrent in the service line or indoor service line. When a current or short circuit occurs, the current is quickly interrupted. Therefore, short-circuited wires Protected from hazards due to high current loads and at the same time power distribution via unshorted lines The power supply of power consuming devices connected to the network is maintained uninterrupted. Similarly, the salary The electrically energized distribution network busbars are protected against overload and are therefore Regular shutdown can be avoided.

Use in each case for lines in outdoor distribution systems and lines in cable distribution networks Therefore, overcurrent protection devices for all wires in one service line are integrated into one common protective case. - installed in the housing. This protective casing is designed to be robust against impacts one input end for each conductor and neutral conductor of the drop-in line, if It is equipped with a terminal and one output terminal. In certain applications, two or more One common protective casing for overcurrent protection devices for more than one service line. In some cases, it may be appropriate to provide one.

In various embodiments of the invention, the structure of the switchable overcurrent protection device according to the invention The outcome will be different. Next, these implementation side tubes will be briefly explained.

Electromechanical contactors are used as breakers in overcurrent protection devices. corresponding restrictions The unit is distributed! Two relays for magnetic actuation, connected as a power supply to one of these two relay current circuits has a switching contact. one for the separation of the child, the other for its closure, each for one semiconductor Series connection between body switch element and one excitation coil? We are prepared. Minute of switching contact The semiconductor switch element of the electric circuit is connected to the overcurrent detector signal. and/or company, the excitation current is controlled by the signal generated in the event of a short circuit in the service line. cut off the flow. To close the switching contact for reconnecting the power consumer The semiconductor switching element of the relay current circuit is equipped with a monitoring device to connect all the excitation currents. control by a signal arriving again at the plate, i.e., eliminating the cause of the overcurrent or short circuit. be controlled. For electromagnetic operation with excitation direct current, the relay current circuit is routed through a grid rectifier. connected to the electricity grid.

Designed for this purpose, in order to separate the switching contacts with a short activation time when interrupting the current. The relay current circuit that is connected to a power source with The same means a for closing the switching contact This switching contact is implemented in a similar manner to this can be closed when connecting the current in a shorter operating time than without Ru.

Distribution grid thyristors t-equipped semiconductors connected in parallel in opposite directions to each other A protective switch is used as a breaker. Its control unit controls both syris a control pulse generator with one output common to the body switches are connected in parallel. The control pulse generator is placed in the network, the control pulse This suppresses the pulses connected to the power supply to form the power distribution network of Shipreka. The conduction of the SIRISK is controlled to allow alternating current (load current) to flow. Retraction In the event of an overcurrent or short circuit in the line, that of the two grid thyristors In order to disconnect the load equipment by each automatic arc extinguishing, the semiconductor switches mentioned above are used. The conduction is controlled by the overcurrent detector signal or the short circuit detector signal, and in this way On the control output side, a signal from the monitoring device is sent to reconnect the load equipment current. As a result, the overcurrent detector signal is held shorted at 1 which is terminated.

In this embodiment of the switchable overcurrent protection device, the breaker In the series connection of a mechanical contactor and one choke coil, connect them in parallel in opposite directions to each other. A semiconductor protective switch with a power distribution grid thyristor connected in parallel It is made up of a lot of things. In this case, the semiconductor protective switch can e.g. As an auxiliary means for separating switching contacts without switching arcs during t-breaks used. What happens when overcurrent occurs in the series-connected choke coils mentioned above? Due to the increase in current, a pulse-type voltage is formed, and this pulse-type voltage is used as a semiconductor protective switch. is applied to the grid and ignites the grid thyristor, resulting in this grid thyristor being overloaded. Short #8 substituted by the signal of the current detector and/or advantageously by a monitoring device Continuity is controlled by the detector signal. Supplied to the control unit of the semiconductor protective switch Such signals are simultaneously fed to the control unit of the electromechanical contactor, which In this way, the semiconductor elements of the relay current circuit are controlled to separate the switching contacts, An exciting current is connected instead. This signal to the control unit of the contactor is In order to continuously control the distribution thyristor, the cut-off time of the electromechanical contactor is is supplied for a long time and in this way the grid thyristor can be connected to itself. The switching contact remains conductive to the applied current and is thus separated from the one It is maintained in a state where only a small amount of current flows through itself. Cause of overcurrent or short circuit Pi The signal of the monitoring load sent after alt-removal is sent to the control unit of the electric machine A contactor. In this way, the semiconductor switch in the relay current circuit controls As a result, the switching contact is closed, and for this purpose an exciting current is applied to the input liquid α.

Such a signal simultaneously causes the switching contacts of the electromechanical contactor to close without switching arcs. It is supplied to the In unit of the semiconductor protection switch when it is necessary to do so.

For this purpose, the distribution network thyristor of the semiconductor S-switch is activated by this signal, and the electromechanical The contactor must remain conductive for a long time.

Next, the invention will be explained based on an example using figures.

1st [F] is VDE 0100 7'! 1-’2 / 03. According to part 83 FIG. 2 Schematic diagram of an overcurrent protection device according to the invention for a high-voltage device configured 3 is a block circuit diagram of the overcurrent protection device of the present invention in the first embodiment described above, and The figure is a block circuit diagram of the overcurrent protection device of the present invention in the second embodiment described above. Figure 4 is a block circuit diagram of the overcurrent protection device of the present invention in the third embodiment described above. be.

In each of FIGS. 2 to 4, the overcurrent protection device of the present invention is applied to a six-phase line. It is shown for only one phase tm. Identical segment lines in different figures (by the same reference numerals).

Next, the present invention will be explained based on an example using figures.

In Figure 1, the part indicated by the symbol E, that is, the part for power supply to houses and buildings. Only the indoor lead-in part of the high-voltage current device is shown. The indoor lead-in part On the right side next to the indoor lead-in line 1 starting from the point where it enters the property H and the branching point V of the strip-shaped Hyukome line. The part of the equipment in Figure 1 located at It is.

Retraction I! 1', the indoor drop-in line l is connected to the distribution network busbar of the power distribution network N, and the drop-in line 1 An overcurrent protection mechanism 0 is additionally provided in the middle of ', and overcurrent protection W & U are overcurrent protection It can be opened and closed differently from the protector @U. In Figure 1, the overcurrent protection mechanism U is is provided directly behind the branch point AN of the lead-in line 1' from the bus line. That is, -φ1 in the middle of each phase Is l/R and 1's and l'T of the lead-in line 1' One overcurrent protection mechanism U is provided, and this lead-in wire 1' is connected to the power distribution network busbar of the power distribution network N. And indoor retraction I! 1, it is three-phase, i.e., this lead-in line 1' has a neutral line as well as a neutral line. Fully equipped with phase current. Branch point AN of another three-phase drop-in line from the same distribution network busbar is shown on the right side of FIG.

Each of these lines is routed into a separate building and has identical switchable overcurrent protectors. It is equipped with a structure.

The overcurrent protection mechanism of the present invention has the ability to open and close the breaker Lt by a hole provided inside the breaker Lt. The circuit breaker L is connected to a control unit S, optionally equipped with a signal amplifier. If an overcurrent flows through a current line equipped with an overcurrent protection mechanism, the circuit will open immediately. He thus interrupts the current in this current line. The cause of overcurrent is removed. When the current is removed, current flows through the current wire again. Overcurrent is equipped with current sensor W8t. The overcurrent detector generates a signal as detected by the control unit. is supplied to input 1 of St. Breaker L is controlled each time) St. By virtue of the operative connection with the output m, it is actuated to realize the corresponding operation.

The above-mentioned components, St, O, and D act together with "at", and the current i in the three-phase service line 1' 6 overcurrent protections that can be opened and closed between 1'R, 1'8, and l'T The mechanism is provided in one common protective casing G. Inside the protective casing G The feature of the overcurrent protection @ structure is the above-mentioned passage 9, and this is shown in passages 20 to 41. and in each figure one of three identical such protection mechanisms is A current protection mechanism U' is shown.

The overcurrent protection mechanism SR shown in FIG. at switch) Sch k s Available in switching contact pair K and ' shown in closed position. The switching contact pair K and K has one fixed switching contact and one switching contact pair K and K. It consists of a rotating switching contact. Its control unit) St is for electromagnetic operation. Consisting of two relay current circuits, each of these two relay current circuits A magnetic coil e1 or e2 and one non-contact relay switching element, ie, a thyristor T1 or T2, excitation coil e1 and non-contact relay switching element, ie, thyristor T1 am'i is formed in series with the excitation coil e2 and the non-contact type relay switching element, that is, the Star T2 is a serial liquid.

These two series connections are connected in parallel with each other, and this parallel connection is It is connected to the output side of the grid rectifier G1. This grid rectifier G1 is connected to the grid rectifier G1. Lance Tr f: Connected to the distribution network phase 1ll (R in this case) through this The current line to be protected (in this case 1'R) is branched off from the grid phase line.

The excitation coil is movable within and along the coil axis and is rod-shaped. Magnet 1! 11 or m2t - cylinder winding with each, magnet m1 or m2t m2 is a rotatable switching contact that mechanically interlocks with the protruding rod member. It is formed like a sea urchin. In FIG. 2, this protruding rod member is oriented toward the switching contact K. Mechanical interlocking is indicated by one arrow tip in each indicated by the line. The input side It- of the control unit St of the thyristor T1 The ignition signal from the overcurrent detector (described later) is supplied to the control electrode forming the An excitation current flows through the coil e1, thus forcing the switching contact K into the open state 1. action is triggered. Input side It of control unit St - forming side (by the ignition signal of the monitoring device 11IO, which will be described later), which is supplied to the control electrode of the restarter 20. An excitation current flows through the coil e2, thus bringing the switching contact Kt into the closed state. This action is triggered by the corresponding protrusion member. Each of the aforementioned lines of action is Control unit 8t0, indicated by (2), forms one operating output side.

In Figure 2, two relay current circuits comprising thyristors T1 and T2 are One push-pull circuit is completely formed, and this push-pull circuit handles overcurrent every time. It is actuated by the excitation current flowing in the coil e1 according to the signal of the detector, and the next Then, the excitation current flows into the coil e2 due to the signal from the monitoring gI structure 0. When the excitation current disappears, the operation stops.

As shown in Figure 2, a push-pull circuit is provided on the erase capacitor C and the power distribution The network rectifier G1 provides an uninterrupted DC voltage or an overcurrent detector signal. If the signal is extended by the sending of the signal 1 of the monitoring mechanism 0, it is connected to the thyristor T1. The connected excitation current is connected such that the second excitation current of thyristor T2 flows. , so that the thyristor T1 is forced to extinguish this second excitation current to flow at l: The thyristor T1 is connected so that the excitation current flows through the thyristor T2. is forcibly erased at I, and the same process is repeated.

The advantage of this method is that the switching contact and K are respectively then In the switching position, there is a similarly acting hand normally used in mechanical breakers. It is securely fixed regardless of the presence or absence of a stage, and furthermore, the other switching of the end of the stage is The point is that the changeover into position is accelerated by actuating means that assist each other in the process. Ru.

The same advantage applies to the use of thyristors T1 and T2 as semiconductor switching elements. The control signal from the overcurrent detector and the monitoring device go are replaced by a transistor. The control signal from the next overcurrent detector and the control signal from the monitoring device @0. If extended in transmission 1 with the control signal, the grid rectifier feeding the relay current circuit can be obtained if it supplies an uninterrupted DC voltage.

The means for accelerating the switching operation of the switching contact of the electromechanical contactor is the overcurrent shown in Fig. 2. In the protection mechanism, for capacitor C shown on the left side of this (2), Control charging switch SL f using a charging circuit equipped with a switching contact t each , they are separated from each other in a much shorter operating time than without the charging circuit, and as a result The response delay of the operating means of the relay current circuit, which is troublesome, can be further reduced. Mitsuru The electrical circuit is connected via a rectifier to an additional secondary winding MWz of the distribution network transformer Tr; Additional secondary winding W,! , is a voltage several times higher than the voltage supplied to the current regulator G1. Designed for pressure. This increases the weight per unit output of the transformer. do not have to. Capacitor C is connected via one resistor and charging switch SL, The bill is charged to a high DC voltage, and the charging switch SL is set at a voltage of 10 to 20 mm, for example. Designed for the desired short operating time of seconds. Both sides! Electrical current circuit has charging A high DC voltage is supplied from the output a of the circuit.

The above-mentioned overcurrent detector and also the above-mentioned monitoring mechanism 0 are shown in FIG. The remaining 9 Keyaki parts of the overcurrent protection device U are also configured. overload as indicated When the current protection mechanism is 0', the switching contacts K and K of the overcurrent protection mechanism 6' Current between the output terminal of the current protection mechanism U and 1? l l'R1-, current edge l'8 It is used as a current sensor Wst for detecting overcurrent generated in the motor. current Two probe lines f are connected to the edge 1'it, and the probe if is a discriminant. connected to the input side of the bridge full-wave rectifier circuit Gr via the motor or filter circuit F. ing. A threshold value at is connected to the output side of the bridge full-wave rectifier circuit ()r, and the threshold value Stage 8t is connected in front of a flip-flop comprising an amplifier.

Component part? , Gr, st, and k work together with st to form an overcurrent detector. Ru. Output of overcurrent detector @output side of all 7 lip-flops forms and clips The output side of the 70 tube is connected to the green signal, while the control input side 1 of the control unit 8t, i.e. connected to the control electrode of the thyristor T1 and, on the other hand, the control electrode of the aforementioned charging circuit. The force is biased and connected.

The filter circuit F extracts the induced component of the voltage tapped from the current tal'□. The threshold value at is configured only to pass through, and the threshold value at is such that this dark value is triggered in the event of a short circuit. The change in current that occurs in the lead wire 1'8 (if it exceeds the voltage value of the induced component equal to li/at) It is determined that there will be no. In this way, the threshold price signal is generated only for fg and case freezing. In this way, the contactor 8ch is disconnected from the output side to the flip-flop. Operation to open the switching contact 'f trigger 7, in the charging circuit of the capacitor C. An ignition signal is generated to cause the charge flow to flow. This firing signal is already Occurs in the event of a short circuit, resulting in a short circuit between operations triggered in this way The current first increases 1. This short circuit current then increases the voltage of the distribution network from the shorted service line. switching contact force before it becomes large enough to drop excessively at the branch point; open state. It is blocked by . As mentioned above, overcurrent detectors additionally detect short circuits. For example, an overcurrent detector is configured to detect an overcurrent that does not occur. For example, with an additional threshold value, the input side of this additional threshold value is an additional bridge adjustment. It is connected to the probe line through a flowmeter, and this globe line is connected @ in front of the filter circuit F. It is branched from f.

The output of this threshold value is connected to the input of a flip-flop. This threshold The stage threshold is determined such that the ignition signal is generated when the overcurrent reaches a predetermined value. It is being

The monitoring mechanism 0 of the overcurrent protection mechanism in FIG. 2 essentially consists of two voltage converters W1 and W2. A voltage divider consisting of two primary windings W1 and w2 connected in series. Consists of. This voltage divider is connected to the current line 1' in the protective casing G of the overcurrent protection mechanism. Connect the input side connection terminal Kl of 8 and the output side connection terminal KIA of the neutral wire MP, This voltage divider is therefore used for the phase voltages present between the phase line R and the neutral line MP of the distribution network. It's flowing. The voltage dividing point formed by the connection of primary windings w1 and w2 has a current of 1! It is connected to the output terminal KIA of l'. to the primary winding W2 of the voltage converter W2. Part of the current line 1/ and neutral @MP are connected to the output side connection terminal KIA, and this A signal converter is connected to the secondary winding vs of the voltage converter W2. This signal converter , a bridge rectifier Gr is downstream connected on the input side, and then a converter stage U is connected. The output of the converter stage U is connected to the control input l of the control unit St. The control electrode of star T2 is connected. Power is being supplied to the indoor terminal (contact (Channel 8ch is in a closed state), an AC voltage is applied to the secondary winding W8, and This AC voltage depends on the transformation ratio of W2 vs/w2x? ), suitable for signal formation has a small amplitude value as part of the amplitude value of the grid phase voltage. In the secondary winding ws The AC relief voltage disappears when a short circuit occurs in the drop-in line 1'8, and this AC voltage becomes not present unless the drop-in wire is shorted or bridged with low resistance, or is too small for signal formation. The AC voltage in the secondary winding ws is short-circuited or overloaded. The flow will occur again as soon as the cause of the flow is removed. Bridge full wave of the signal converter mentioned above This alternating voltage is passed through the rectifier circuit and converter stage U to the thyristor T of the control unit st. 2, and this rectangular control signal causes the excitation current to The operation of closing the switching contact for reconnection, which flows through the coil e2 and injects the current. is triggered. The length of the control signal is determined from the recovery of the alternating voltage in the secondary winding mvs. First, by limiting the duration to less than that required for the closure of the switching contacts K and K. This is advantageous, since the excitation current is interrupted after the switching contacts K and K are closed. It is et al.

As mentioned above, the control signal formed by the monitoring mechanism 0 and having a limited duration and the control signal, which is formed by the overcurrent detector and has a limited duration, is Instead of thyristors, transistors are used as semiconductor switching elements T1 and T2. , these transistors are controlled by these control signals, or Turn-off thyristor or single-elimination thyristor 2) When used in St., it has the above-mentioned purpose.

The signal converter of monitoring mechanism 0 replaces converter U with a flip-flop for signal formation. , and a threshold value pre-connected to this, in this way short circuits or Set a sufficiently high dark value if the cause of overcurrent has not been completely eliminated. This ensures the transmission of the control signal and thus the closing of the switching contacts K and K accordingly. It is also possible to prevent it.

In this case, as explained in (2), instead of an electromechanical contactor, a reciprocal Completely equipped with two distribution grid thyristors Th1 and Th2 connected in parallel. A semiconductor protective switch is used as a breaker. In Figure 3, Corresponding control unit) St is equipped with a control pulse generator, and this control pulse generator is the power supply used for forming the control pulses via the voltage converter W2' of the monitoring mechanism 0. It is connected to the power distribution network N. For this purpose, voltage converters control the required power. In order to supply the control pulse generator, the distribution is connected to a network traverse with a corresponding transformation ratio W8/W2. It is configured similarly to the Regardless of the configuration of the voltage converter W2, the monitoring mechanism O is It is used for its own original function and at the same time as a short circuit detector. Therefore overcurrent In the above-described embodiment of the overcurrent protection mechanism, the detector It is additionally provided only if it must be shut off when an overcurrent value of . In FIG. 3, this overcurrent detector is shown together with its components f, Gr, st, and k. Connections to the current sensor with probe wire ft-at are shown, but the connection to the probe wire ft- Not yet. This overcurrent detector signal detects an overcurrent in the phase line l'□ of the service line. If a flow occurs, this is connected in parallel to the output side of the control unit) St. In this case, the semiconductor switch Tk, which is a switching transistor, is controlled to be conductive, and Then, the control input m is short-circuited.

Therefore, control pulses are supplied to the distribution network thyristors Th1 and Th2 of breaker L. Therefore, the current conduction state of the distribution network thyristors Th1 and Th2 is self-extinguished. The arc is terminated and the load current is interrupted. The switching transistor is the short circuit detector signal. Conduction is also controlled by the signal. Monitor @O for reconnecting the load current The signal is reset to the flip-flop stage of the overcurrent detector via the signal line r1. supplied to the input side, Tk is therefore cut off, so that the control pulses are supplied to the breaker L power distribution grid thyristors.

A control pulse with control capability is supplied to the secondary winding 1ivrs of the voltage converter W2. , the phase alternating current voltage UR′f that is lowered by the transformation ratio below 1 and is applied to the load equipment. By rectifying and converting the voltage generated by the bridge rectifier Gr and the conversion stage U, Ru. The bridge rectifier Gr and the conversion stage U constitute a control pulse generator ttm, as shown in FIG. As in the embodiment of the overcurrent detector shown, the monitoring mechanism O is connected downstream. This is the component that is included. The monitoring mechanism without any other means controls the control pulse generator. Together with the voltage converter W2 configured as a grid transformer, it can also be used as a short-circuit detector. It is configured. When a short circuit occurs in the drop-in line 1', the voltage applied to the voltage converter W2 is The phase alternating current voltage face disappears, so that no control pulses are generated. Bree Each of the two thyristors is automatically extinguished when the load current passes through zero, and the load The current is interrupted. In the course of the time current when the load current is short-circuited, the voltage The amplitude of the phase alternating current voltage applied to the converter W2 is determined by a control pulse having controllability. It becomes so small that it cannot be achieved. After interrupting the load current, as long as there is a short circuit, The phase AC voltage OR is applied to the voltage converter W1 of the monitoring mechanism 0. After short circuit removal This phase AC voltage UR is temporarily caused by the distribution network thyristor of breaker L being conductive. Unless there is is being applied. The turns ratio w’l/wl of the primary winding of the transformer is the primary winding The phase AC voltage UR on the line W2 is calculated by considering the transformation ratio v2/vs of the voltage converter W2. be selected to be large enough to form a control pulse system with ignition capability. It will be done. When the distribution network thyristors Thi and Th2 become conductive, the phase AC voltage U R is again applied to the primary winding of voltage converter W2.

Another one of the overcurrent protection mechanism 6'□ shown in FIG. 4 and explained in (3) In the embodiment, the breaker L includes the semiconductor protection switch shown in FIG. The electric machine shown in Fig. 2 is connected in series with the coil (series choke coil Dr). In combination with a physical contactor, this semiconductor protective switch and this electromechanical contactor are connected in parallel with each other. In this example, the load current is normally In some cases, this is supplied via permanently closed electromechanical contactors.

Semiconductor protective switches are used as auxiliary switching means to prevent short circuits or overcurrents from occurring in service lines. If this occurs, this auxiliary switching means will ensure that the switching contacts K and K are Isolated from each other with small current loads or without arcing.

In both cases, the semiconductor protection is opened by a signal from the overcurrent detector and/or monitoring mechanism 0. The circuit breaker is made conductive, and in this case, when the short-circuit current 1 rises, the choke coil D The distribution network thyristor, which is loaded in the forward direction by a voltage pulse formed at the point arc and conduction control.

In this way, a low-resistance bypass of the choke coil against short-circuit currents is provided to the contactor. Even when channel 8 is closed, it is fired, resulting in a bypass current branch and A short circuit rising up through the lead-in wire 1'8 which is short-circuited by the neutral wire MP. Most of the current flows through the current 1, and the current path passing through the contactors Sch and Dr is quite slow. is loaded by a correspondingly small component of the short-circuit current 1, which increases to . Overcurrent protection The signals of the contactor and/or monitoring mechanism are simultaneously transmitted to the control unit of the electromechanical contactor, the vessel supplied and thus for the separation of the excitation current switching contacts of the relay current circuit Connected. At the end of the disconnection time of the contactor Sch, the switching contacts are separated from each other, When the small component of the short-circuit current 1 is interrupted, the short-circuit current 1 is bypassed. The component diverted to the flow branch continues to flow further and the self Once the arc is extinguished, it will be shut off when the next current zero point passes. The overcurrent protection mechanism shown in Figure 4 Following the explanation regarding the contactor Sch and the choke coil Dr t-current, A breaker consisting of a parallel connection of a branch path and a current branch path that generates noise above a semiconductor protective switch. A functionally appropriate embodiment of L will be described in connection with an example (feeder &) Ru.

In the overcurrent protection mechanism equipped with breaker L shown in Figure 4, the The control unit for the mechanical contactor is the control unit shown in FIG. The thyristors T1 and T2 and two of the t1 push-pull circuits are configured similarly to h. It is used as a semiconductor switch element in relay circuits. 10 for contactor cut-off time For additional reduction below m5ec, the control as shown on the left of Fig. 2 is carried out. The unit may also be equipped with a charging circuit. Distribution network thyristor for semiconductor protection switchgear The control unit for Thi and Th2 has a signal input side l and a control output side m. t, and the signal input @l is derived from the conversion stage U of the monitoring mechanism 0. the control output m is connected to a grid thyristor, which Irista is controlled in a similar manner to the control unit in Prisoner 3. Figure 4 Control unit) St, however, connects the two relay current circuits from the grid rectifier G1. Power is supplied via the connection. The overcurrent protection mechanism shown in Figure 4 can be used as an overcurrent detector depending on the situation. The overcurrent detector and the monitoring mechanism are It is provided in common to the contactor Sch and the thyristors Th2 and Th2. Figure 4 The overcurrent protection mechanism shown in Figure 1 has only monitoring mechanism 0 for this nine, and this monitoring Mechanism 0 is simultaneously used as a short circuit detector.

For this purpose, the control function of conversion stage U is configured accordingly, for example with one signal output and One control for thyristor 1 and T2 of control unit St of contactor Sch The control output side has a negated frigflow with the required time constant. connected to the input side of the control unit St for the semiconductor protection switch via the It is. From the control output side of the conversion stage U, to the secondary winding mvs side of the voltage converter W2. In this case, a rectangular sustained pulse with a step-like trailing edge and controllability is generated when the alternating voltage is It is taken out when it falls below a predetermined value. This control output side is, on the one hand, the control unit's control It is connected to the control input side 1 (control electrode of thyristor T2), and on the other hand, it is connected to The control input l (control electrode of thyristor T1) )It is connected. If a short circuit occurs in the lead-in wire 1'8, in the secondary winding vs. The alternating current voltage disappears, so that a controllable continuous pulse is generated on the control output side of the converter stage U. On the signal output side, the signal of the conversion stage is sharply interrupted. this In this way, a sustained pulse with controllability is supplied to the control electrode of thyristor T1. Then, the excitation current for separating the switching contact is connected. At the same time, semiconductor protection energizes the control unit for the switchgear with a power grid thyristor that can be fired each time A control signal is supplied to the electromechanical contactor and the duration of this control signal is It is longer than the quick cutting time of Connected by the semiconductor protection switch after the control signal has terminated. The commutation current is reduced by the self-extinguishing of the conducting thyristor when the current passes through the next zero point. and its reconnection in reverse polarity by the second grid thyristor. There will be no sequel. The primary winding of the voltage converter W2 to which the distribution network phase voltage UR is applied The lines are components of the inductive voltage divider W1 and W2 of the monitoring mechanism 0, and the primary winding By removing the short circuit, the voltage is restored again, and the AC voltage is restored to the secondary winding again. It will be done. As mentioned above, in this way, from the control output side of the conversion stage U, the control (22) A sustained pulse is extracted that has the ability to control the semiconductor switch element T2 of St. At the same time, the sustained pulse that suddenly maintains the conduction state of the semiconductor switch element Til+ disappears. Switching contacts K and K are also switched off so that grid rectifier G1 carries uninterrupted direct current. When supplied, they are separated from each other. Supplied to the electrode of semiconductor switch element T2 The excitation current for closing the switching contact is connected by a sustained pulse. Ru.

As can be seen from FIGS. 4 and 2, switching means q is connected in series with the voltage dividers W1 and W2. This switching means q is, for example, an electromagnetically remotely actuated break contact. normally held closed by an excitation current, but separated from each other by a short circuit. Covalent operation with switching contacts K and K is switched to the open state, and in this open state, the excitation current is cut off to the switching means q. It is located at L. For this purpose, the excitation current circuit starts from the switching means q and is connected to the output loop. is derived from the protective casing G via the output clasp KIAk in the form of a retraction f/iJ 1 ', and is installed at the indoor lead-in part E1 (see Figure 1). In this way, Overcurrent protection buried underground together with distribution network cables and drop-in cables In the machine casing, after repairing the lead-in cable that was destroyed due to a short circuit, the switching means q is Shifting the contacts to the closed position by remote control will prevent damage to the drop-in cable. Repairing broken line loops eliminates exposure to grid voltage hazards. It is possible without. Voltage dividers W1 and W2 are therefore connected to the grid voltage and switched Reclosing of the contacts takes place. Remotely controlled switching means q can also be used as a semiconductor relay. can be constructed and further used in the embodiment shown in FIG. Can also be done.

As an example of a power supply device, the power distribution network, 0.5! o length of the distribution network busbar, i.e. the normal Suburban house with 10 indoor connections powered by low voltage cable VPE Consider power supply equipment for the earth. 10 lines in parallel from this bus line in a residential area. All connected service lines branch out, and these service lines connect individual apartments and small housing complexes. guided by. Each service lead is rated for 100A current consuming equipment at a connection voltage of 220V. formed for current, each drop-in wire has three phase wires 1'R, 1's and 1'T and a neutral @MP. Note that short circuits in only the phase wires and short circuits in the neutral wire may also occur. As a consideration, each phase line of the drop-in line must be equipped with an overcurrent protector ei5'. . Due to the destructive action, the phase wires and neutral wires on all sides were In this case, the lines 1'R and l's The phase currents 1R, 1s and IT flowing in each of the 1'T are, respectively, phase short-circuit currents 'k)R, 1k)8 and 'k)T, and these phase short-circuit currents 'k) ) R and 1k) 8 and 1k) T are the same as the respective polarity of the phase current at the moment of short circuit. begins to increase. During half-wave oscillations of the phase currents, the earlier the point of short circuit During this half-wave oscillation, the time constant of the short-circuit current circuit -"1s/Rrn The relevant phase short-circuit current during the start-up time given by is high. however Rm is the resistance of the phase line ph (ph-R, S, T) of power distribution @N, and L is the resistance of the phase line ph (ph-R, S, T). The inductance of Suph (ph-R + St T) is used, and 18 is a choke coil. is the inductance of Dr. In case of a short circuit in three phase wires, these A short circuit in one of the wires is not important, since a short circuit is Occurs before the end of the half-wave oscillation of the phase currents at an excessively small time interval such as 81, and therefore Therefore, a short circuit occurs entirely in at least one of the other phase wires. Ru. The time course 41k(i) is that the phase ph of the distribution network during the rise time of the short circuit A simplified control in which the generator voltage Eph is constant and has an effective value iph. can be well approximated to below ca.

Therefore, the general generator voltage Eph is the effective value of each phase voltage Uph for power consumption crisis. The value is also determined to be V at the rated load of the three-phase power distribution network. The following formula (1 ) is based on the time variation of short circuits in the relevant phase line 1' and in the distribution network phase line. (1ph(0) is the current value of 100 people flowing through the phase at time t-Q. ).

In equation (1), the capacity current and the derived current of the three-phase power distribution network line (R8T, MP) are The influence of the section of the phase line between the input terminal Kl and the output terminal Kl can be ignored. Resistances as small as possible (FIG. 4) are not taken into account.

However, what should be taken into consideration is that according to equation (1), the time change of the short-circuit current is The inductance is influenced by the inductance 18 of the choke coil Dr between The tank 18 is branched from the three-phase Tm bus and connected in parallel with each other. Of the 0 lead-in wires 1', the remaining 9 wires are not short-circuited in this example. It is a point that exists on the phase line 1; h. The time change changed in this way is Specific data for a 0.5 km long low voltage cable for a 3-phase distribution network bus H Rm-0,12Ω and LM = O-125mH and Is = 0.5mH Therefore, as a special solution for 1k(0)=10OA, the following formula (2) can be used as a special solution. can.

(2) 1k(t) = (-9,17 notes, +95.1)・exp-0,654t(A ) From equation (2), the current rise speed aik7 at the time of short circuit (0) -0, You can earn 77K.

-92,5A/ Therefore, at the time of short circuit, the voltage pattern with pulse height di/dt(0) IB Luz to Chalk Phil Dr. At 18-0.05 mH, the pulse height is 8.5v.

This voltage pulse connects the shorted electromechanical contactor 8ch of phase m1'8. A semiconductor protection switch (fourth factor) installed in the bias current branch path with the coil The forward-biased power distribution grid iris resistor shown in In order to inject and connect the short circuit current into the ias current branch path, the state becomes conductive. same At the same time, the short circuit detector 00 firing signal provides both circuits of the semiconductor protection switch to network safety risk. be provided. The inductance of the choke coil Dr is determined from equation (2), ik The value d1 of the raising speed of the tiger hat is set according to /dt (0), and therefore, it is fired. It has the pulse height necessary to control conduction of the thyristor. Furthermore, Chalk Phil Dr. , the pulse height of the voltage pulse is about Q, and there is a cine change during 1 m5ec, so , for example 15 μsec, delayed due to inhibition and obtained in a thyristor. It is configured to enable conduction control with a longer connection time than the connection time. . The suitable choke coil for this purpose is the alternating current of seven magnetic cores! Permeability due to magnetic field Due to and such a choke coil has a circular or preferably rectangular shape for +i reasons. So-called single wire choke carp with a tape core made of soft abrasive material. The tape core Drk is configured as a They are stacked adjacent to each other on ml'□. Choke coil like this For example, a tape core consisting of a small number of silicone-tech style plates can be used. Each core of these tape cores has a railway length of 25crR and 4CI With a core height of n, a core area of 6.8d, and a kW, each is applied to the clamping device. It's really tight. The number of tape cores required for this is determined by The number of cores is determined by the size of the gap between the separation surfaces (0, 0 11 to 0.1 ff1m) 4 to 12 depending on K.

Choke coil Dr with identical action and suitability for the desired shape of the voltage pulse For example, cobalt is about 504, and the corresponding size is the difference between cobalt and iron. It can also be made with multiple tape cores made of alloys. Furthermore, for this purpose, A circular ring-shaped core made of ferrite material can also be used. For example, the railway chief The diameter is medium at 25c211, the core height is 1.53''?', and the core cross-sectional area is 2.5 fl”, such a ring-shaped core has the above-mentioned characteristics. It takes 40 pieces to make a choke coil, but a ring-shaped core like this It is not necessary to provide a void, because the length of the railway of the ring-shaped core is o, o i decreases by several times the value of aj, and thus the hysteresis loop of the ring-shaped core decreases This is because the directional deformation (scherung) is sufficiently strong.

Choke coil inductance 18 and choke coils stacked on each other The sum of the core heights of the cores and the voltage at the time of separation of the switching contact of the contactor Sch The current value can also be determined, and the contactor 8ch and choke coil Dr are connected to this current value. The short-circuit partial current 12 flowing in the current branch path provided with the bypass current branch path A large short-circuit partial current 11 flowing in the circuit is closed by a semiconductor protective switch. It will increase and reach later. The time change of the flow part 11 and 1□ is the time change of equation (2). It can be obtained as a special solution determined by equation 1k(t). The left-hand side of equation (2) The second term is so small that it can be ignored even in the case of t - Q, 5 m5ec, Therefore, equations (1) and (2) are one and the same exponential function e It only has xp −0,654. Therefore, 〜mel 咄 is the above value. , l5-0-05 mH, from equation (2), the choke coil Dr' (Temporal change of flowing current 1□) The following equation (3) is obtained.

The resistance of the bypass current branch path is measured in mΩ. The unit of resistance of the current branch path is mΩ, and U8 is the resistance of the t44 thyristor. Threshold effective value of Th, unit is V, t is short circuit current duration, unit is m8e It is e.

The bulk resistance (equivalent resistance) of the tq thyristor is in the range of 0.16 to 0.2 mΩ. In return, the threshold voltage is 1.1V. For example, both 't' are tape-shaped current conductors. The resistance rl and r of the IL flow branch path, rB + rl, is about 0.3 mΩ, Cry is determined to be approximately 0.6 mΩ. Therefore, from equation (3), we can see that the choke The partial current 1□ in the coil Dr and the closed switching contacts K and K is t -i　Q　In m5ec, initial value 1ph (0) - Increased from 10OA to 43OA The result is that we add This is the maximum value of the partial current 12 in this example. , and this maximum value requires that the point of short circuit occurs very early when the phase current is 10 and a half hours. It can only be reached if it is located in a wave vibration. Only in this case, and electromechanical Only when the switching time of contactor Bch is less than iQ rnsec, the switching connection is The contactors are separated from each other when the current load is maximum. In contrast, the data From the formula for 11, which is not described in this specification, the commutated part When the current 11 is t-5m5ec, it reaches the maximum value of 2660A, and at t-10 In this case, it can be seen that it is 2470A.

Generally, from equation (3), the choke coil Dr is the sum of resistances rB + rz + r As long as 2 is less than 0.1 mΩ, if the inductance is larger than 18, The increase in partial current 12 is reduced beyond the initial 4FL1ph(0) at the time of the short circuit. I understand that. For example, O-1mH = Is, other short circuit current circuits If there is no change in the above data of In the case of 175 people, the initial current is 1ph(0)'! It increases again and again. of partial current Another way to reduce the increase is to have the threshold voltage U8 below lvh. Use Star Thwo. For this purpose, a thyristor connected to the substrate common Appropriate. For example, Is = 0-1 mH, Us -0.6v, Otherwise, if the above data remain the same, the partial current 12 is t-i[]m5 The ecLv case increases by 127 people over the initial current.

By reducing the current increase, switching contacts K and K reduce the current flow through the portion 12. in some cases separated from each other. In this case to the east there is a large probability that the switching arc is stable or if the switching contacts are separated. , no damage to the switching contacts, only sparks generated during switching.

In the embodiments described above, the protective device tk of the invention can be used without essential modification, e.g. Networks between factories, autonomous distribution of networks for vehicles, ships, etc. (other than public AC power distribution networks) It can also be used for power supply from the national power distribution network). Power supply from DC distribution network For this purpose, the arrangement must be a network thyristor, a thyristor that is forcibly erased, or a corresponding control. The control means uses a high-t resistor that can be switched off and used.

international search report international search report EP8ε00180 SA　21092

Claims (9)

[Claims] 1. The distribution network (N) is branched from the phase wires (R, S, T) of the distribution network (N). - Indoor lead-in part (connected by electric wires (1'R, 1'S, 1'T)) E) one overload each to protect the wires (1R, 1S, 1T) in the area Equipped with a current protection device (■), it is suitable for indoor electrical equipment such as houses and factories, e.g. In the overcurrent protection device for device (A), additionally one overcurrent protection device ( ■') in each of the above-mentioned lead-in wires - electric wires (1'R'1'S'1'T) of the lead-in wire (1'). , provided immediately after the branch point (AN) of the lead-in line (1') from the power distribution network (N). , the overcurrent protection device includes a breaker (L) and a control for operating the breaker (L). unit, and the lead-in wire (1') of the lead-in wire-electric wire (1'R'1'S'1'T ), when an overcurrent occurs in the circuit breaker, the control unit Equipped with an overcurrent detector (D) and a monitoring device (O), which supply a signal to control the interruption. Prepared, Once the cause of the overcurrent has been removed, the control unit is instructed to restart the current by the breaker. and a monitoring device for supplying a signal for controlling an incoming connection. protection device. 2. Overcurrent protection device for all drop-in wires - electric wires (1'R'1'S'1'T) (■') in one common protective casing (G) The protective casing is impact-resistant and can be closed airtight. and the connection between each lead-in wire (1'R'1'S'1'T) and the neutral wire (MP). Equipped with one input terminal and one output terminal (K1E or K1A) for The overcurrent protection device according to claim 1, characterized in that: 3. the overcurrent detector (D) comprises a flip-flop stage (k); A threshold value (st) is connected to the input side of the flip-flop stage (k), the threshold value (st) is connected to the output side of a bridge full-wave rectifier (Gr); The input side of the bridge full-wave rectifier is connected to a current sensor (Ws t), the threshold value (st) is connected to the sensitivity of the current sensor (Wst), and The current cutoff control is determined depending on the fixed minimum value of the current increase. The overcurrent protection device according to claim 1, having a threshold value serving as a reference. 4. The chain coil (Dr) (directly connected in series with the breaker (L)) A claim characterized in that a current sensor (Wst) is used as a current sensor (Wst). The overcurrent protection device according to item 3. 5. The monitoring device (O) is connected to the two primary windings (w) of the two voltage converters (W1, W2). 1, w2) in series with one voltage divider consisting of The voltage divider is connected to the drop-in wire to be protected by the lead-in wire (1'R'1'S'1'T). Applied between the branching power grid phase wires (R, S, T) and the neutral wire (MP) Connect so that the voltage that is applied is applied. The connection between the two primary windings (w1, w2) is connected to the lead-in wire-wire (1'R) to be protected. Connect to the output side connection terminal (K1A) of '1'S'1'T), The primary winding (W2) connects the signal that controls the current re-connection with the neutral wire (MP). From the secondary winding (ws) of the voltage converter (W2), which is The signal is supplied to the control unit (St) via the signal converter (Gr, U). The overcurrent protection device according to claim 1. 6. The breaker (L) is an electromechanical contactor (Sch), The corresponding control unit (St) is configured to operate the switching contact (K) electromagnetically. Equipped with two relay current circuits, One of the relay current circuits is connected to an overcurrent detector ( D) and/or by the disappearance of said signal of said overcurrent detector (D). When the current is cut off by the semiconductor switch element (T1) which is controlled to The contactor (K) is separated and the other of said relay current circuits is connected to the cause of overcurrent or short circuit. The conduction is controlled by the semiconductor which is sent out again from the monitoring device (O) after removing the fault. When the current is re-connected by the body switch element (T2), the switching contact (K) Close the Each of both said relay current circuits has one excitation coil for one actuation magnet. (e1, e2) and connected to a DC power supply (G1) supplied from the power distribution network (N). The overcurrent according to any one of claims 1 to 5, characterized in that the overcurrent is Protective device. 7. At least a relay current circuit for electromechanically separating the switching contact (K) is connected to the DC voltage charged in the capacitor (C) when the excitation current is applied and connected. Continuing, Claim 6, characterized in that the DC voltage is greater than the voltage of the DC voltage source (G1). Overcurrent protection device described in . 8. Distribution network silis in which the breakers (L) are connected in parallel in opposite directions to each other It is a semiconductor protection switch equipped with a switch (Th1, Th2), The corresponding control unit (St) has a control pulse generator and a grid thyristor (Th 1, Th2) have a common control output side, On the control output side, the semiconductor switch (TK) receives a signal from an overcurrent detector (D). conduction by automatically extinguishing the distribution network thyristors (Th1, Th2). A semiconductor connected in parallel to the control output side when the current is controlled to be interrupted. Short-circuited by body switch (TK), The signal of the overcurrent detector (D) is connected to the power distribution network thyristor (Th1, Th2 ) is sent from the monitoring device (O) in order to reconnect the current by controlling the conduction. According to any one of claims 1 to 5, the method lasts until the signal is sent out. Overcurrent protection device as described. 9. A breaker (L) connects the electromechanical contactor and the series chain coil (Dr). In the column connection, distribution network thyristors (Th1, T h2) is connected to a semiconductor protection switch equipped with said electromechanical contactor (Sch) is provided with a corresponding control unit (St); The semiconductor protection switch comprises a control unit (St) comprising a signal amplifier. , Electromechanical contactors and protective switches have a common overcurrent detector (D) and monitoring device (O) and A signal from the overcurrent detector (D) is provided to the control unit of the semiconductor protection switch. and/or a signal formed when the signal of said monitoring device (0) disappears. conduction control of the power distribution network thyristors (Th1, Th2), and so that the current is commutated to the semiconductor protective switch, simultaneously supplying said signals to said control unit of said electromechanical contactor (Sch); , for both control units for a duration exceeding the disconnection time of said electromechanical contactor (Sch). supply in time, On the other hand, in order to reconnect the power consuming equipment, the signal of the monitoring device (O) is , the semiconductor switch of the relay current circuit for re-closing the switching contacts (K, K) Claims 1, 2 and 4 characterized in that the element (T2) is supplied with at least 7. The overcurrent protection device according to any one of 7.