CA2092442C - Ac/dc-converter - Google Patents
Ac/dc-converter Download PDFInfo
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- CA2092442C CA2092442C CA002092442A CA2092442A CA2092442C CA 2092442 C CA2092442 C CA 2092442C CA 002092442 A CA002092442 A CA 002092442A CA 2092442 A CA2092442 A CA 2092442A CA 2092442 C CA2092442 C CA 2092442C
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- rectifier
- convertor
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- supply
- phase
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
- H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
- H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
- H02M3/285—Single converters with a plurality of output stages connected in parallel
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
- H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
- H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
- H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
- H02M7/08—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode arranged for operation in parallel
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P80/00—Climate change mitigation technologies for sector-wide applications
- Y02P80/10—Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
Abstract
AC/DC convertor to connect to conductors of a multi-phase AC source and a plurality of parallel to each other power factor correction circuitries. There are as many rectifier circuits independent of each other as there are phases of the AC source. Each rectifier circuit has six rectifier elements connected in pairs to the conductors of the AC source and are commonly connected to the output conductors of the rectifier circuit associated therewith forming bridges. There is at least one switch associated with at least one pair of rectifier elements to separate such pair from the conductor of the AC source. Each rectifier circuit is connected to a power factor correction network. Sensors are used for the functional control of both of the phases of the AC source and the one phase power factor correction network. There is a switch control logic connected with such sensors and which based on the signals from the sensors closes or opens the switches of the rectifier network.
Description
AClDC COP1VERTOR
This invention relates to an AC/DC convertor for connection to a multi-phase AC network and to an operating procedure of such convertor.
AC/DC convertors for connection to a multi-phase network are known. For example US patent 5,045,991 discloses a convertor which, with the aid of a six-pulse controlled bridge rectifier, rectifies a 3 phase AC
current.
DE patent 37 38 181 A1 discloses a current rectifier whose output DC current is controlled by a steady in phase switching of six bridge rectifier elements. The difference between the two patents is in the control logic where, especially in the first mentioned patent, the alternating current of the network remains approximately sinusoidal even at varying load.
United States Patent 5,003,453 discloses an AC/DC convertor with equal loading of the three phases of a 3 phase network. This convertor is fed, in one version, by all three phases and in another version with a single one of the three phases of the network three parallel power factor connection circuits. These supply, at their outputs, DC current which is then changed again through a DC/DC convertor for the various loads requested by a computer complex. The AC/DC convertor is built manyfold redundant and is able, during interruption of a network phrase, or a power factor connection circuit, or a DC/DC convertor; to deliver the current that is required by the computer. This AC/DC convertor is quite complicated and specially built to deliver the diverse loads of a large scale computer, and the computer operation is mod interrupted even when the convertor needs to be worked on (repaired).
The aim of the present invention consists of building a regulated, redundant AC/DC convertor for general usage, which is simple in its structure and which is independent in its current delivery capability during considerable interface. Also it should be flexible with respect to its output values.
In keeping with the foregoing there is provided in accordance with the present invention AC/DC convertor for connection to the line conductors of a multi-phase AC
supply, which has, as a means of preventing complete outage, a redundant design and loads the AC supply substantially without non-linear distortion, and where a plurality of parallel-arranged power factor correcting circuits are provided, characterized in that provided are a number of identical rectifier circuits, which are independent of each other and correspond to the number of phases of the supply, provided are six rectifying elements per rectifier circuit, said rectifying elements being connected in pairs to lines of the supply and in being connected to output leads of rectifier circuits respectively, form bridges, at least one switch is provided for each of said rectifier circuits with such switch or switches operating in conjunction with at least one pair of rectifying elements and being designed to separate each respective pair from the circuit of supply to which each such pair is assigned, one single-phase power factor correcting C7.rCU7.t is arranged downstream of its respective rectifier circuit, provided are sensors to monitor operation of the phases of the supply and of single-phase power factor correcting circuits, and provided is a switch control that is connected via leads to said sensors and which, depending on the signals from the sensors, opens or closes the switches of the rectifier circuits.
The invention is illustrated by way of example in the accompanying drawings wherein:
Figure 1 is a schematic block diagram of an AC/DC convertor of the present invention for connection to a three phase network;
Figure 2 illustrates schematically a first variation of the rectifier circuit;
This invention relates to an AC/DC convertor for connection to a multi-phase AC network and to an operating procedure of such convertor.
AC/DC convertors for connection to a multi-phase network are known. For example US patent 5,045,991 discloses a convertor which, with the aid of a six-pulse controlled bridge rectifier, rectifies a 3 phase AC
current.
DE patent 37 38 181 A1 discloses a current rectifier whose output DC current is controlled by a steady in phase switching of six bridge rectifier elements. The difference between the two patents is in the control logic where, especially in the first mentioned patent, the alternating current of the network remains approximately sinusoidal even at varying load.
United States Patent 5,003,453 discloses an AC/DC convertor with equal loading of the three phases of a 3 phase network. This convertor is fed, in one version, by all three phases and in another version with a single one of the three phases of the network three parallel power factor connection circuits. These supply, at their outputs, DC current which is then changed again through a DC/DC convertor for the various loads requested by a computer complex. The AC/DC convertor is built manyfold redundant and is able, during interruption of a network phrase, or a power factor connection circuit, or a DC/DC convertor; to deliver the current that is required by the computer. This AC/DC convertor is quite complicated and specially built to deliver the diverse loads of a large scale computer, and the computer operation is mod interrupted even when the convertor needs to be worked on (repaired).
The aim of the present invention consists of building a regulated, redundant AC/DC convertor for general usage, which is simple in its structure and which is independent in its current delivery capability during considerable interface. Also it should be flexible with respect to its output values.
In keeping with the foregoing there is provided in accordance with the present invention AC/DC convertor for connection to the line conductors of a multi-phase AC
supply, which has, as a means of preventing complete outage, a redundant design and loads the AC supply substantially without non-linear distortion, and where a plurality of parallel-arranged power factor correcting circuits are provided, characterized in that provided are a number of identical rectifier circuits, which are independent of each other and correspond to the number of phases of the supply, provided are six rectifying elements per rectifier circuit, said rectifying elements being connected in pairs to lines of the supply and in being connected to output leads of rectifier circuits respectively, form bridges, at least one switch is provided for each of said rectifier circuits with such switch or switches operating in conjunction with at least one pair of rectifying elements and being designed to separate each respective pair from the circuit of supply to which each such pair is assigned, one single-phase power factor correcting C7.rCU7.t is arranged downstream of its respective rectifier circuit, provided are sensors to monitor operation of the phases of the supply and of single-phase power factor correcting circuits, and provided is a switch control that is connected via leads to said sensors and which, depending on the signals from the sensors, opens or closes the switches of the rectifier circuits.
The invention is illustrated by way of example in the accompanying drawings wherein:
Figure 1 is a schematic block diagram of an AC/DC convertor of the present invention for connection to a three phase network;
Figure 2 illustrates schematically a first variation of the rectifier circuit;
Figure 3 illustrates schematically a second variation of the rectifier circuit; and Figure 4 is a block diagram of a control arrangement.
Referring to the drawings Figure 1 is a schematic block diagram of an AC/DC convertor 10. This convertor 10 is connected to the three phases 12, 13, 14 of a three-phase network which is represented by the generator 15. Each of the three phases 12, 13, 14 connects to a three phase network with phases R, S, T. A
neutral phase is not necessary and therefore not shown.
The phases 12, 13, 14 are connected on the primary side and in parallel to three rectifier circuitries 20, 30, 40 which connect to respective ones of one phase power factor correction units 21, 31, and 41.
Outputs 22, 23; 32, 33; and 42, 43 of the respective units 21, 31 and 41 are connected in parallel to a variable load 60, represented as an ohmic resistor.
The AC/DC convertor 10 consists further of a control and switch logic 50 which are connected with the DC rectifier circuits 20, 30, 40 and the power factor correction units 21, 31, 41.
The three rectifier circuits 20, 30, 40 are built the same and each contains six rectifiers shown as six diodes designated 24-29, 34-39, and 44-49. Each diode is serially associated with a switch and these are designated 124-129, 134-139, 144-149 for the respective rectifier circuits 20, 30 and 40. The diodes and switches of each rectifier circuit 20, 30, 40 are connected in a six-pulse controlled bridge rectifier in pairs to the conductors 12, 13, 14 and in threes via respective connections 122, 123; 132, 133; and 142, 143 to respective power factor correction units 21, 31, 41.
In a normal case, i.e. defect free operation, two pairs of switches in each of the respective groups 124-129; 134-139; and 144-149 are closed (i.e. switched for current conduction) in the rectifier circuits 20, 30, 40 and the remaining two switches are open (i.e. no current conduction). The open and closed switches are chosen in such a way that in each rectifier circuit 20, 30, 40 a different open switch is assigned to the conductors 12, 13, 14. In Figure 1 for example, the pair of switches 128, 129 are open in the rectifier circuit 20 and assigned to conductor 14, the pair of switches 136, 237 are open in the rectifier circuit 30 and assigned to conductor 13, and the pair of switches 144, 145 are open in the rectifier circuit 40 and assigned to conductor 12.
A11 other switches are closed. With this arrangement each rectifier circuit 20, 30, 40 works as a one phase bridge rectifier that is assigned to one of the phases R, S, T of 'the three phase AC currents. At the connections 122, 123; 132, 133; and 142, 143 to the .respective power factor correction units 21, 31, 41 the voltage has been derived from one phase rectification of a quasi sinusoidal waveform.
The three one-phase power factor correction units 21, 31, 41 are identical and work independent from each other. Each one of those networks 21, 31, 41 delivers at their respective outputs 22, 23; 32, 33; and 42, 43 a regulated DC current at any adjustable output voltage. The networks are built in such a way that the described one phase pulsing rectified voltage at the inputs 122, 123; 132, 133; and 142, 143 are used mostly without nonlinear distortion. The load on the generator 15 (i.e. the AC network) is therefore similar to that of an ohmic load so that conductors 12, 13, 14 essentially are free of higher harmonics which could cause interference with other equipment. Such a power factor connection unit is described e.g. in European patent 0218 267.
Further characteristics of the one-phase power factor connection circuits 21, 31, 41 are the galvanic separation between input and output as well as the size.
The galvanic separation is the reason why, as described, C
-the outputs 22, 23; 32, 33; and 42, 43 can be connected together at any potential. The sizing can be made in such a way that always two of the three units 21, 31, 41 can provide the maximum power. Therefore, in the case of a failure of one of the units 21, 31, 41 there is no loss of power to the user or load 60.
The control and switching logic 50 controls the switches 124-129; 134-139: and 144-149 of the rectifier networks 20, 30, 40 common and in pairs in the open state via the corresponding control signal conductors 224, 226, 228; 234, 236, 238: and 244, 246, 248. The control signal information is fed via signal conductors 222, 232, 242 for example from connections 122, 123; 132, 133; and 142, 143 and over conductors 221, 231, 241 from the power factor correction units 21, 31, 41.
The AC/DC convertor 10 works as follows:
During defect free, normal operation each .rectifier circuit 20, 30, 40 the alternating current, which is sinusoidal, and is derived through the changing of the phases R, s, T of the three phase alternating current according to a triangle or delta connection. There is no need for the switches 124°129, 134-139, 144-149 to operate. They remain in the described normal position.
The power factor correction units 22, 31, 41 produce a regulated direct current of a high quality from the accordingly generated one°phase pulsing rectifier current. The three units deliver the power required by the load essentially in equal parts.
If for any reason one of the power factor correction units 21, 31, 41 fails then this condition is transmitted to the control and switching logic 50 via the corresponding signal lines 221, 231, 241. The control and switching logic reacts by opening all switches of the corresponding rectifier circuit 20, 30, 40 thereby disconnecting the failing part of the convertor 10 from the generator 15. The remaining two power factor correction units 21, 31, 41 will now automatically increase their power output thereby continuing to deliver to the load 60 an unchanged current.
If one of the phases R, S, T of the generator 15 is lost then this condition will be transmitted to the control and switching logic over at least one of the signal lines 222, 232, 242. In this case logic 50 closes all up to now open switches of all three rectifier circuits 20, 30, 40 and enables therefore an emergency operation. The remaining voltages between lines 12, 13, 14 are essentially still sinusoidal so that all rectifier circuits 20, 30, 40 and the power factor correcting units 21, 31, 41 that follow work essentially unchanged. The rectifier diodes provide the necessary decoupling in this ~~~l~~l~
case. In order to improae the decoupling it is also possible to open those switches via logic 50 that are associated with the lost phase R, S, T.
The AC/DC convertor 10, in its described construction, possesses in many respects redundancy which is simple and can be used in cases of disturbances so that a mostly secure current supply to the load 60 can be guaranteed.
Figure 2 schematically illustrates a variation 201 which may be substituted for one of the rectifier circuits 20, 30, 40. This circuit 201 contains as described six diodes 24-29 but only two switches 128, 129 which are associated with the pair of diodes 28, 29.
These switches, in this example associated with conductor 14, will be open during normal, uninterrupted operation and will be closed if one of the phases R, S, T is interrupted.
Figure 3 schematically illustrates yet another variation 202 of the rectifier circuit. This circuit 202 has only a single switch 128a. This switch 128a is associated with diodes 28, 29 and connected to conductor 14. This switch functionally replaces the two switches 128, 129 of the variation according to Figure 2.
In principle switches 124-129; 134-139; 144-149 and 128a can be electromagnetic switches, e.g. the contacts of a relay or circuit breaker since the switches are switched very seldom and there are no special requirements for the actual switching operation, e.g. a requirement that the switching can only take place at zero voltage. However, a preferred solution would use controlled semi-conductors as for example thyristors as triacs, especially when combined in a single unit with the diodes for the rectifier function and the switching function. The switches according to Figures 1 and 2 may be unipolar. The switch 128a in Figure 3, however, must be a bi- polar switch.
Figure 4 shows in a block diagram form, a simple controller .for phases R, s, T of a three-phase AC
generator 15 as well as the associated switching logic 50. Three voltage controllers 70, 71, 72 serve as sensors which are connected in a triangular fashion to the conductors 12, 13, 14. Logic 50 is made of a logical and with an inverted output 51. This output can be used to control the thyristors directly via the amplifiers 54, 59. The thyristors represent switches 24-29.
It is basically possible to use any convertor for the power factor correction units 21, 31, 41 that produces a direct current out of a rectified sinusoidal alternating current. However, no linear distortions are allowed to be fed back into the resistor 15 and preferably it should provide a voltage decoupling. Such a known convertor is described in the European patent 0 218 267. There the voltage decoupling is achieved through a controlled bridge switch followed by a 'transformer and rectifier. It is advantageous when the power factor correction units 21, 31, 41 are built as high/low (boot/buck) placers because this way the flexibility of the ratio input voltage (i.e. voltage between conductors 12, 13, 14) to output voltage (i.e.
voltage between outputs 22, 23; 32, 33; and 42, 43) can be made very large.
The outputs of the power factor correction units 21, 31, 41 can, with appropriate voltage decoupling, be connected to a simple load 60. But it is also possible that each unit 21, 31, 41 can be connected to a separate load and these loads need be equal.
The construction of the AC/DC convertor 10 is relatively simple and robust. Tt can be connected to the generator or AC network 15 without a neutral or ground connector. The convertor is flexible and adaptable to many special applications. A very good characteristic is its redundancy and therefore satisfies the high demands for security against interruptions. The switches described are only operated during a power failure and therefore do not require continuous operation. The convertor 10 is therefore a comparatively very useful device for almost any application.
Referring to the drawings Figure 1 is a schematic block diagram of an AC/DC convertor 10. This convertor 10 is connected to the three phases 12, 13, 14 of a three-phase network which is represented by the generator 15. Each of the three phases 12, 13, 14 connects to a three phase network with phases R, S, T. A
neutral phase is not necessary and therefore not shown.
The phases 12, 13, 14 are connected on the primary side and in parallel to three rectifier circuitries 20, 30, 40 which connect to respective ones of one phase power factor correction units 21, 31, and 41.
Outputs 22, 23; 32, 33; and 42, 43 of the respective units 21, 31 and 41 are connected in parallel to a variable load 60, represented as an ohmic resistor.
The AC/DC convertor 10 consists further of a control and switch logic 50 which are connected with the DC rectifier circuits 20, 30, 40 and the power factor correction units 21, 31, 41.
The three rectifier circuits 20, 30, 40 are built the same and each contains six rectifiers shown as six diodes designated 24-29, 34-39, and 44-49. Each diode is serially associated with a switch and these are designated 124-129, 134-139, 144-149 for the respective rectifier circuits 20, 30 and 40. The diodes and switches of each rectifier circuit 20, 30, 40 are connected in a six-pulse controlled bridge rectifier in pairs to the conductors 12, 13, 14 and in threes via respective connections 122, 123; 132, 133; and 142, 143 to respective power factor correction units 21, 31, 41.
In a normal case, i.e. defect free operation, two pairs of switches in each of the respective groups 124-129; 134-139; and 144-149 are closed (i.e. switched for current conduction) in the rectifier circuits 20, 30, 40 and the remaining two switches are open (i.e. no current conduction). The open and closed switches are chosen in such a way that in each rectifier circuit 20, 30, 40 a different open switch is assigned to the conductors 12, 13, 14. In Figure 1 for example, the pair of switches 128, 129 are open in the rectifier circuit 20 and assigned to conductor 14, the pair of switches 136, 237 are open in the rectifier circuit 30 and assigned to conductor 13, and the pair of switches 144, 145 are open in the rectifier circuit 40 and assigned to conductor 12.
A11 other switches are closed. With this arrangement each rectifier circuit 20, 30, 40 works as a one phase bridge rectifier that is assigned to one of the phases R, S, T of 'the three phase AC currents. At the connections 122, 123; 132, 133; and 142, 143 to the .respective power factor correction units 21, 31, 41 the voltage has been derived from one phase rectification of a quasi sinusoidal waveform.
The three one-phase power factor correction units 21, 31, 41 are identical and work independent from each other. Each one of those networks 21, 31, 41 delivers at their respective outputs 22, 23; 32, 33; and 42, 43 a regulated DC current at any adjustable output voltage. The networks are built in such a way that the described one phase pulsing rectified voltage at the inputs 122, 123; 132, 133; and 142, 143 are used mostly without nonlinear distortion. The load on the generator 15 (i.e. the AC network) is therefore similar to that of an ohmic load so that conductors 12, 13, 14 essentially are free of higher harmonics which could cause interference with other equipment. Such a power factor connection unit is described e.g. in European patent 0218 267.
Further characteristics of the one-phase power factor connection circuits 21, 31, 41 are the galvanic separation between input and output as well as the size.
The galvanic separation is the reason why, as described, C
-the outputs 22, 23; 32, 33; and 42, 43 can be connected together at any potential. The sizing can be made in such a way that always two of the three units 21, 31, 41 can provide the maximum power. Therefore, in the case of a failure of one of the units 21, 31, 41 there is no loss of power to the user or load 60.
The control and switching logic 50 controls the switches 124-129; 134-139: and 144-149 of the rectifier networks 20, 30, 40 common and in pairs in the open state via the corresponding control signal conductors 224, 226, 228; 234, 236, 238: and 244, 246, 248. The control signal information is fed via signal conductors 222, 232, 242 for example from connections 122, 123; 132, 133; and 142, 143 and over conductors 221, 231, 241 from the power factor correction units 21, 31, 41.
The AC/DC convertor 10 works as follows:
During defect free, normal operation each .rectifier circuit 20, 30, 40 the alternating current, which is sinusoidal, and is derived through the changing of the phases R, s, T of the three phase alternating current according to a triangle or delta connection. There is no need for the switches 124°129, 134-139, 144-149 to operate. They remain in the described normal position.
The power factor correction units 22, 31, 41 produce a regulated direct current of a high quality from the accordingly generated one°phase pulsing rectifier current. The three units deliver the power required by the load essentially in equal parts.
If for any reason one of the power factor correction units 21, 31, 41 fails then this condition is transmitted to the control and switching logic 50 via the corresponding signal lines 221, 231, 241. The control and switching logic reacts by opening all switches of the corresponding rectifier circuit 20, 30, 40 thereby disconnecting the failing part of the convertor 10 from the generator 15. The remaining two power factor correction units 21, 31, 41 will now automatically increase their power output thereby continuing to deliver to the load 60 an unchanged current.
If one of the phases R, S, T of the generator 15 is lost then this condition will be transmitted to the control and switching logic over at least one of the signal lines 222, 232, 242. In this case logic 50 closes all up to now open switches of all three rectifier circuits 20, 30, 40 and enables therefore an emergency operation. The remaining voltages between lines 12, 13, 14 are essentially still sinusoidal so that all rectifier circuits 20, 30, 40 and the power factor correcting units 21, 31, 41 that follow work essentially unchanged. The rectifier diodes provide the necessary decoupling in this ~~~l~~l~
case. In order to improae the decoupling it is also possible to open those switches via logic 50 that are associated with the lost phase R, S, T.
The AC/DC convertor 10, in its described construction, possesses in many respects redundancy which is simple and can be used in cases of disturbances so that a mostly secure current supply to the load 60 can be guaranteed.
Figure 2 schematically illustrates a variation 201 which may be substituted for one of the rectifier circuits 20, 30, 40. This circuit 201 contains as described six diodes 24-29 but only two switches 128, 129 which are associated with the pair of diodes 28, 29.
These switches, in this example associated with conductor 14, will be open during normal, uninterrupted operation and will be closed if one of the phases R, S, T is interrupted.
Figure 3 schematically illustrates yet another variation 202 of the rectifier circuit. This circuit 202 has only a single switch 128a. This switch 128a is associated with diodes 28, 29 and connected to conductor 14. This switch functionally replaces the two switches 128, 129 of the variation according to Figure 2.
In principle switches 124-129; 134-139; 144-149 and 128a can be electromagnetic switches, e.g. the contacts of a relay or circuit breaker since the switches are switched very seldom and there are no special requirements for the actual switching operation, e.g. a requirement that the switching can only take place at zero voltage. However, a preferred solution would use controlled semi-conductors as for example thyristors as triacs, especially when combined in a single unit with the diodes for the rectifier function and the switching function. The switches according to Figures 1 and 2 may be unipolar. The switch 128a in Figure 3, however, must be a bi- polar switch.
Figure 4 shows in a block diagram form, a simple controller .for phases R, s, T of a three-phase AC
generator 15 as well as the associated switching logic 50. Three voltage controllers 70, 71, 72 serve as sensors which are connected in a triangular fashion to the conductors 12, 13, 14. Logic 50 is made of a logical and with an inverted output 51. This output can be used to control the thyristors directly via the amplifiers 54, 59. The thyristors represent switches 24-29.
It is basically possible to use any convertor for the power factor correction units 21, 31, 41 that produces a direct current out of a rectified sinusoidal alternating current. However, no linear distortions are allowed to be fed back into the resistor 15 and preferably it should provide a voltage decoupling. Such a known convertor is described in the European patent 0 218 267. There the voltage decoupling is achieved through a controlled bridge switch followed by a 'transformer and rectifier. It is advantageous when the power factor correction units 21, 31, 41 are built as high/low (boot/buck) placers because this way the flexibility of the ratio input voltage (i.e. voltage between conductors 12, 13, 14) to output voltage (i.e.
voltage between outputs 22, 23; 32, 33; and 42, 43) can be made very large.
The outputs of the power factor correction units 21, 31, 41 can, with appropriate voltage decoupling, be connected to a simple load 60. But it is also possible that each unit 21, 31, 41 can be connected to a separate load and these loads need be equal.
The construction of the AC/DC convertor 10 is relatively simple and robust. Tt can be connected to the generator or AC network 15 without a neutral or ground connector. The convertor is flexible and adaptable to many special applications. A very good characteristic is its redundancy and therefore satisfies the high demands for security against interruptions. The switches described are only operated during a power failure and therefore do not require continuous operation. The convertor 10 is therefore a comparatively very useful device for almost any application.
Claims (16)
1. An AC/DC convertor for connection to line conductors of a three-phase AC supply, which has, as a means of preventing complete outage, a redundant design and loads the AC supply substantially without non-linear distortion, and where a plurality of parallel-arranged power factor correction circuits are provided, characterized in that provided are three identical rectifier circuits, which are independent of each other and which correspond to the three phases of said supply, provided are six rectifying elements per rectifier circuit, said rectifying elements being connected in pairs to said line conductors of said AC supply and in being connected to output leads of said rectifier circuits respectively, form bridges, at least one switch is provided for each of said rectifier circuits, with each said switch operating in conjunction with at least one pair of said rectifying elements and being designed to separate each respective pair from said line conductors of said AC supply to which each said pair is assigned, a single-phase power factor correction circuit is arranged downstream of its respective rectifier circuit, provided are sensors to monitor operation of the phases of the AC supply and of the single-phase power factor correcting circuits, and provided is a switch control that is connected via leads to said sensors and which, depending on the signals from the sensors, opens or closes the switches of the rectifier circuits.
2. The AC/DC convertor as defined in claim 1, characterized in that said three-phase AC supply is a generator with three line conductors and no neutral and no ground conductor.
3. The AC/DC convertor as defined in claim 1, characterized in that for each rectifier circuit a single switch is used which is accordingly associated with a pair of rectifier elements of said line conductors of said three-phase AC supply, and where each rectifier circuit of the associated switch is connected to said line conductors.
4. The AC/DC convertor as defined in claim 1, characterized in that for each rectifier circuit two switches are used, which are connected in series with the two rectifier elements associated with the pair of switches, and where in each rectifier circuit the appropriate switches and rectifier elements are associated with another. line conductor of said three-phase AC supply.
5. The AC/DC convertor as defined in claim 1, characterized in that for each rectifier circuit six switches are used which are connected individually and in series with the six rectifier elements of the associated rectifier circuits.
6. The AC/DC convertor as defined in claim 1, characterized in that said at least one switch is built as an electrically controllable semi-conductor switch.
7. The AC/DC convertor as defined in claim 1, characterized in that said at least one switch together with the corresponding rectifier element is built as a common electrically controlled unit.
8. The AC/DC convertor as defined in claim l, characterized in that each said one-phase power factor correction circuit is connected to a separate load.
9. The AC/DC convertor as defined in claim 1, characterized in that each said one-phase power factor correction circuit is built as a convertor with galvanic separation, and that these said convertors are connected to a common load.
10. The AC/DC convertor as defined in claim 9, characterized in that said convertors are built in such a way that two of said convertors are sufficient to supply the common load.
11. Operation of an AC/DC convertor according to claim 3 characterized in that during disturbance free operation a switch is open in a rectifier circuit for each of the respective phases of a three-phase AC supply and that when one of the phases of the three-phase AC
supply is interrupted then all switches of the remaining phases will be closed for the duration of the interruption.
supply is interrupted then all switches of the remaining phases will be closed for the duration of the interruption.
12. Operation of an AC/DC convertor according to claim 4, characterized in that during disturbance-free operation two switches in each rectifier circuit are open, and that at the time of an interrupt of one of the phases of a three-phase AC supply all switches of the remaining phases are closed for the duration of the interruption.
13. Operation of an AC/DC convertor according to claim 5, characterized such that during disturbance-free operation of the convertor, four switches in each rectifier circuit associated with two pairs of the rectifier elements are closed, and two of the switches that are associated with the third pair of the rectifier-elements are open, each rectifier circuit of the corresponding open switches and the corresponding rectifier-elements are assigned to another line conductor of the three-phase AC supply, all switches that were open during normal operation will be closed for the duration of an interruption.
14. Operation as defined in claim 13, characterized such that during interruption of one of the phases additionally all these switches are opened that are associated with said line conductor of the interrupted phase.
15. Operation as defined in claim 13, characterized in that at the time of failure of one of the one-phase power factor connection units and for the duration of the failure all switches will be opened that belong to the rectifier circuit that is connected to the failing power factor connection unit.
16. In an AC/DC convertor for connection to the line conductors of a three-phase AC supply and a plurality of power factor correction units the improvement comprising three identical rectifier circuits which are independent of each other, each said rectifier circuit having six rectifying elements connected in pairs to the supply lines with at least one switch operating in conjunction with at least one selected pair of rectifying elements to selectively separate the same from the power supply line associated therewith, a single-phase power factor correcting means downstream of the respective rectifier circuits, and sensor means to monitor operation of the respective phases of the AC supply and power factor correcting means and provide signals that actuate the switches of said rectifier circuits.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH00991/92-9 | 1992-03-27 | ||
| CH99192 | 1992-03-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2092442A1 CA2092442A1 (en) | 1993-09-28 |
| CA2092442C true CA2092442C (en) | 2002-06-11 |
Family
ID=4199920
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002092442A Expired - Fee Related CA2092442C (en) | 1992-03-27 | 1993-03-25 | Ac/dc-converter |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US5406470A (en) |
| EP (1) | EP0562662B1 (en) |
| JP (1) | JPH06311751A (en) |
| CA (1) | CA2092442C (en) |
| DE (1) | DE59306487D1 (en) |
Families Citing this family (27)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0731510Y2 (en) * | 1990-05-16 | 1995-07-19 | 矢崎総業株式会社 | Female terminal fitting |
| SE503374C2 (en) * | 1994-11-15 | 1996-06-03 | Asea Brown Boveri | Method and apparatus for controlling a series compensated rectifier station included in a system for transmitting high voltage direct current |
| US5523938A (en) * | 1995-06-07 | 1996-06-04 | Sundstrand Corporation | Differential current fault protection for an AC/DC hybrid system and method therefor |
| US5894414A (en) * | 1997-03-03 | 1999-04-13 | Lucent Technologies Inc. | Three phase rectifier using three single phase converters and a single DC/DC converter |
| FR2772526B1 (en) * | 1997-12-17 | 2000-02-11 | Schneider Electric Sa | ALTERNATIVE-CONTINUOUS THREE-PHASE CONVERTER |
| US5956244A (en) * | 1998-03-05 | 1999-09-21 | Allen-Bradley Company Llc | Controlling currents in parallel AC/DC converters |
| WO2001045230A1 (en) * | 1999-12-16 | 2001-06-21 | Mcandrews Enterprises Inc. | Spare bus power plant |
| WO2002065611A1 (en) * | 2001-02-16 | 2002-08-22 | Yanmar Co., Ltd. | Power system having generator driven by engine |
| AU2002339815A1 (en) * | 2001-05-21 | 2002-12-03 | Marconi Intellectual Property (Ringfence) Inc. | Power systems power circuits and components for power systems |
| US6501192B1 (en) * | 2001-11-16 | 2002-12-31 | Eni Technology, Inc. | Three phase rectifier circuit with virtual neutral |
| US20040061380A1 (en) * | 2002-09-26 | 2004-04-01 | Hann Raymond E. | Power management system for variable load applications |
| US6801027B2 (en) * | 2002-09-26 | 2004-10-05 | Itt Manufacturing Enterprises, Inc. | Power conversion in variable load applications |
| US6936997B2 (en) | 2003-08-11 | 2005-08-30 | Semiconductor Components Industries, Llc | Method of forming a high efficiency power controller |
| DE102004003657B4 (en) * | 2004-01-24 | 2012-08-23 | Semikron Elektronik Gmbh & Co. Kg | Converter circuit arrangement and associated drive method for dynamically variable output generators |
| JP4341836B2 (en) * | 2004-05-27 | 2009-10-14 | 本田技研工業株式会社 | Portable generator |
| US7456524B2 (en) * | 2006-03-31 | 2008-11-25 | American Power Conversion Corporation | Apparatus for and methods of polyphase power conversion |
| US8300438B1 (en) * | 2008-11-16 | 2012-10-30 | Edward Herbert | Power factor corrected 3-phase Ac-dc power converter using natural modulation |
| US8879286B2 (en) | 2010-07-29 | 2014-11-04 | Sts, Inc. | Facility power supply with power-factor correction |
| RU2515474C2 (en) * | 2011-05-17 | 2014-05-10 | Хонда Мотор Ко., Лтд. | Inverter generator |
| CN102931829B (en) * | 2012-11-09 | 2015-11-25 | 华为技术有限公司 | Circuit of power factor correction and power circuit |
| US9502962B2 (en) | 2012-11-09 | 2016-11-22 | Huawei Technologies Co., Ltd. | Power factor correction circuit and power supply circuit |
| US9479077B1 (en) | 2013-02-04 | 2016-10-25 | Google Inc. | Three-phase power supply system |
| NZ700418A (en) * | 2014-09-25 | 2016-08-26 | Enatel Ltd | Improvements in and relating to load balancing |
| RU2633966C1 (en) * | 2016-11-30 | 2017-10-20 | Юрий Борисович Соколов | Power supply from multi-phase alternating current network with correction of harmonic oscillations |
| DE102017106924A1 (en) * | 2017-03-30 | 2018-10-04 | Airbus Defence and Space GmbH | An electrical power system for an aircraft having a common AC network and a DC bipolar network |
| US10957445B2 (en) | 2017-10-05 | 2021-03-23 | Hill-Rom Services, Inc. | Caregiver and staff information system |
| JP7121971B2 (en) * | 2018-03-21 | 2022-08-19 | 国立大学法人神戸大学 | Three-phase AC-DC converter |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3047848A (en) * | 1957-03-25 | 1962-07-31 | Smith Corp A O | Safety circuit for rectifier power sources |
| US4285023A (en) * | 1980-03-11 | 1981-08-18 | Lorain Products Corporation | Rectifier system with failure alarm circuitry |
| US4680689A (en) * | 1984-01-23 | 1987-07-14 | Donald W. Payne | Three-phase ac to dc power converter with power factor correction |
| DE3840304A1 (en) * | 1988-11-30 | 1990-05-31 | Philips Patentverwaltung | CIRCUIT ARRANGEMENT FOR FEEDING A LOAD |
| US5003453A (en) * | 1989-11-22 | 1991-03-26 | Tandem Computers Incorporated | Apparatus for a balanced three phase AC power supply in a computer having variable DC loads |
| US5045991A (en) * | 1989-12-28 | 1991-09-03 | Sundstrand Corporation | Unity power factor AC/DC converter |
-
1993
- 1993-03-12 DE DE59306487T patent/DE59306487D1/en not_active Expired - Fee Related
- 1993-03-12 EP EP93200722A patent/EP0562662B1/en not_active Expired - Lifetime
- 1993-03-23 US US08/035,650 patent/US5406470A/en not_active Expired - Fee Related
- 1993-03-23 JP JP5088087A patent/JPH06311751A/en active Pending
- 1993-03-25 CA CA002092442A patent/CA2092442C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| EP0562662A1 (en) | 1993-09-29 |
| CA2092442A1 (en) | 1993-09-28 |
| EP0562662B1 (en) | 1997-05-21 |
| JPH06311751A (en) | 1994-11-04 |
| DE59306487D1 (en) | 1997-06-26 |
| US5406470A (en) | 1995-04-11 |
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| Date | Code | Title | Description |
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| EEER | Examination request | ||
| MKLA | Lapsed |