MXPA99005035A - - Google Patents

Info

Publication number
MXPA99005035A
MXPA99005035A MXPA/A/1999/005035A MX9905035A MXPA99005035A MX PA99005035 A MXPA99005035 A MX PA99005035A MX 9905035 A MX9905035 A MX 9905035A MX PA99005035 A MXPA99005035 A MX PA99005035A
Authority
MX
Mexico
Prior art keywords
phase
switches
processor
energy
current sensors
Prior art date
Application number
MXPA/A/1999/005035A
Other languages
Spanish (es)
Original Assignee
David Yair
Friedman Mark M
Target Hitech Electronics Ltd
Wittner Lupu
Filing date
Publication date
Application filed by David Yair, Friedman Mark M, Target Hitech Electronics Ltd, Wittner Lupu filed Critical David Yair
Publication of MXPA99005035A publication Critical patent/MXPA99005035A/xx

Links

Description

APPARATUS AND METHOD FOR THE UNIFORM DISTRIBUTION OF AN ELECTRICAL LOAD THROUGH A DISTRIBUTION NETWORK OF PHASE ENERGY n FIELD AND BACKGROUND OF THE INVENTION The present invention relates to an apparatus and a method for uniformly distributing the electric charge in a three-phase electric power distribution network.
Currently, many residential homes and commercial facilities receive, at their service entrances, the three phases in a three-phase electric power distribution network provided by an electric company or power company. In a three-phase distribution environment each of the phases provides one or more branch circuits. The determination of which circuit or derived circuits to connect to each of the three incoming phases is usually done once the installation is finished. For example, in a residential installation, different branch circuits can supply the kitchen, living room, rooms, etc. with electricity. In a commercial environment, different branch circuits can supply the machinery, offices, etc. A problem that frequently arises is how to distribute evenly the electrical energy through the three incoming phases, provided by the electric company, to all the derived circuits. Often, over time, the topology of the load in a facility will change, sometimes drastically. Some branch circuits will become more heavily loaded and others less heavily loaded, due, for example, to movement of machinery on a factory floor, the addition of a movement of high-wattage appliances (ie, refrigerator, electric stove, oven). microwave, etc.) in a home. Thus, the load in each of the three incoming phases will also change with the load change in the branch circuits. A three-phase network that swung evenly at the start may have unbalanced over time.
One solution to this problem is to reassign each of the branch circuits to an incoming phase to achieve a uniform charge across the three phases by physically rewiring each branch circuit. A disadvantage of this solution is that it potentially requires the expensive rewiring of electrical boxes and electrical panels each time the three phases of unbalance occur, which could frequently occur. Another disadvantage is that the rewiring usually requires an interruption in the energy which causes a potential problem for the customers of the installation. In addition, this solution only provides a raw mechanism to balance the load through the three incoming phases. It does not follow the energy consumption in each of the phases and circuits derived on a frequent basis. The hour-by-hour and minute-by-minute changes in the electrical charges that occur, which could be large enough to cause significant imbalance in the three incoming phases, go unnoticed.
SUMMARY OF THE INVENTION The present invention provides an apparatus for and a method for uniformly distributing the electric load across all three phases of a three-phase power distribution network that overcomes the disadvantages of the above solutions.
According to the teachings of the present invention, a three-phase load distribution system comprising a first, second and third current sensor coupled to a first, second and third phase, respectively, of a three-phase power distribution network is provided. , the first, second and third current sensors for measuring the flow of the electric current through the first, second and third phase, respectively, a plurality of switches, each switch coupled to one of a plurality of branch circuits, each of the plurality of switches to connect any of the first, second and third phase to one of the plurality of branch circuits, a plurality of current sensors, each current sensor coupled to one of the plurality of branch circuits, the plurality of current sensors for measuring the flow of electrical energy through each of the plurality of branch circuits and a processor coupled to the first, second and third sensors, the plurality of switches and the plurality of current sensors, the processor for controlling the plurality of switches so that the flow of electrical current through the first, second and third phase does not exceed a predetermined threshold.
Furthermore, according to the teachings of the present invention, a three-phase load distribution system comprising a first, second and third current sensor coupled to a first, second and third phase, respectively, of a power distribution network is provided. three-phase electric, the first, second and third current sensors for measuring the flow of electrical energy through the first, second and third phase, respectively, a plurality of switches, each switch coupled to one of a plurality of branch circuits, each one of the plurality of switches for connecting any of the first, second and third phases to one of a plurality of branch circuits, a plurality of current sensors, each current sensor coupled to the plurality of branch circuits, the plurality of current sensors to measure the flow of electrical energy through each of the plurality of circuits der ivados and a processor coupled to the first, second and third current sensors, the plurality of switches and the plurality of current sensors, the processor to control _ the plurality of switches so that the differences between electric currents, or proportions of the electric currents, flowing through each of the pairs of the first, second and third phases does not exceed a predetermined threshold.
BRIEF DESCRIPTION OF THE DRAWINGS The invention is described herein, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a block diagram of a three-phase example of the present invention, in which: ) Utility short circuit; B) Switch; * C) Derived short circuit; D) Derived circuit; E) Higher current limit; and F) Processor.
Figure IB is a block diagram of a 1-phase copy of the present invention, in which: A) utility short circuit; B) Switch; C) Derived short circuit; D) Derived circuit; E) Higher current limit; and F) Processor.
Figure 2 is a block diagram of an example of the present invention, in which: A) Adder circuit; B) Rectifier; C) AC generator; D) Derived circuit breakers; and E) Derived circuit.
Figure 2B shows a simple implementation of the additive circuit 52, the rectifier 54, of Figure 2, combining the two functions in a block, three-phase rectifier, 524, in which: A) AC generator; B) CD-CA converter; and C) CD-CA inverter.
Figure 2C is a schematic of a "stationary converter" CD to inverter AC, in which: A) Square AC output; and B) Synchronized AC output.
Figure 2D is a schematic of an inverted CD-to-CA "enhanced converter".
Figure 2E shows a three-phase rectifier and a "stationary converter" CD to inverter AC, with an inductor added to increase the input power factor, in which: A) Synchronized wave output.
Figure 2F replaces the inductor of Figure 2E with a high power factor controller boost interrupt regulator to further increase the input power factor, in which: A) Rectifier output DC with Ripple voltage; B) High power factor controller increase interruption controller, for example, (UC1854); C) Increase regulator (regulated) CD output voltage; D) Retention; E) CD to AC inverter (for example Je CKT); and F) AC output.
Figure 3 is a block diagram of an example of the present invention, which combines the characteristics of the systems of Figures IB and 2F, and which also adds communication capacity, in which: A) Neutral; B) Utility short circuit; C) High energy factor increase converter; E) CD / CA Inverter; F) KN switch; G) Control; H) Derived short circuit, m; I) Derived circuit, n; J) Sensor; K) Processor; and L) Modem.
Figure 4 is an alternative to the implementation of Figures 2 and 2B, in which: A) Module # 1 correction of the energy factor; B) Module # 2 correction of the energy factor; C) Module 3 of correction of the energy factor; D) CD output; and E) Retention.
Figure 5a illustrates the equipment for the energy measurement function, in which: A) Digital electrometer (Kw-Hr meter); B) Data; C) Processor; D) Modem; Y Figure 5b illustrates the equipment for the energy measurement function, in which: A) Processor.
DESCRIPTION OF THE PRE-PLACED EXAMPLE The principles and operation of the present invention can be better understood with reference to the drawings and the accompanying description. • * A block diagram of a device 10 exemplifying the present invention is illustrated in Figure 1. Three-phase electric power, represented by fl, f2, f3, is supplied by an electric power company. The phases fl, f2, f3 are protected against overcurrents by means of a short circuit 14. The output of the short circuit 14 appears at the service entrance to a residence or commercial installation. The current sensors 16, 18, 20 measure the current flowing through the phases fl, f2, f3, respectively. The output of the sensors 16, 18, 20 is monitored by a processor 12. The processor 12 can be any appropriate computing device such as a microprocessor, microcontroller, personal computer, etc.
Each of the. The outputs of the three phases of the circuit breaker 14 are inserted into an array of multipole switches 22, 24, 26, 28, 30. Each switch has four input terminals. Three terminals are provided, each one for each of the three incoming phases. In addition, a fourth terminal is provided which is not a connection terminal (i.e., it is not connected to anything). The output of the switches 22, 24, 26, 28, 30 is introduced to an array of branch circuit breakers 32, 34, 36, 38, 40, respectively. The control signals CONT1, CONT2, CONT3, CONT4, CONT5, leave the processor 12, determine the position of the switches 22, 242, 26, 28, 30, respectively. The output of the branch circuit breakers 32, 34, 36, 38, 40 passes through an array of current sensors 42, 44, 46, 48, 50, respectively, before supplying energy to each of the five branch circuits. Each of the five derived circuits has a neutral N line related to it. The current measured by the current sensors 42, 44, 46, 488, 50 is monitored by the processor 12.
The operation of the device 10 is centered around the multipole switches 22, 24, 26, 28, 30. In the application of the device 10, each branch circuit to be covered has a circuit breaker, a branch circuit breaker and a current sensor. Illustrated in Figure 1 is a load balance system that covers five branch circuits. The present invention, however, could easily be made to cover any number of derived circuits, simply by the proportion of sufficient components.
On a periodic basis, the processor 12 acquires the output of the current sensors 16, 18, 20, which measure the current flowing through each phase of the supplied three-phase power. The processor 12 also monitors the output of the current sensors 42, 44, 46, 48, 50, which measure the current flowing through each of the branch circuits. The time between the successive acquisitions of data from the current sensor is in the order of milliseconds or tenths of milliseconds and is a function of the computer program that controls the processor 12. The data acquired during each data acquisition cycle is not discarded immediately. A finite number of the most recent sets of acquired data are kept in memory, which can be either internal or external to the processor 12.
The processor 12 is appropriately programmed to periodically acquire data from all the current sensors to be able to track the load in each of the phases of the incoming three-phase power and in each branch circuit. When the current measured in any of the phases exceeds a fixed percentage (eg, 90%) of a higher current limit calibration, the processor 12 programs the switches 22, 24, 26, 28, 30 so that the total charge is relatively equal in the three incoming phases. Since the load on a branch circuit is known, the processor 12 can redistribute the derived charges so that the load on each of the phases is approximately equal. Once the new calibrations of the switch are determined, the processor 12 issues switch repositioning commands on the control lines CONT1, CONT2, CONT3, CONT4, CONT5 to the switches 22, 24, 26, 28, 30, respectively.
During the operation of the device 10, it is possible that the load on a single branch circuit is increased to a level that exceeds the maximum allowed derivative current. In response to this possible overcurrent condition, the processor 12 can program the corresponding switch of the branch circuit to its non-connection position. In this position, the branch circuit is electrically disconnected from all three incoming phases. In addition to the overcurrent protection provided by the processor 12, conventional branch circuit breakers 32, 34, 36, 38, 40 also provide overcurrent protection for each of the branch circuits. The device 10 is also capable of providing a conventional function that the circuit breakers are not capable of providing. The processor 12 can be appropriately programmed to predict potential overload conditions before they occur by monitoring the rate of increase in current usage for each of the branch circuits and for each of the incoming phases. Thus, potential power interruptions due to exceeding current limits in an incoming phase can be anticipated and prevented before they occur.
The switches 22, 24, 26, 28, 30 may use semiconductor relays or switches (ie, triacs,, silicon controller rectifiers, etc.) as their central interruption elements. Each switch decodes its corresponding control signal, received from the processor 12, and connects its output to one of the three incoming phases or completely disconnects its output from all three phases. The switches 22, 24, 26, 28, 30 can interrupt their output terminals to any incoming phase fast enough so that devices or equipment connected to their corresponding branch circuit see no fault in the power supplied and thus, no is adversely affected.
The processor 12 derives its energy from fl and the neutral line N from the incoming three-phase power. This processor 12 can, however, derive energy from any of the three incoming phases. The upper current limit calibration can be input to the processor 12 in any number of ways, all well known in the art. For example, the data of the upper current limit could be encoded in a fixed manner in a read-only memory device, provided by external interrupt calibrations, supplied by an external computing device, etc.
While the description of the previous copy has been given with respect to three phases, it should be appreciated that the system of the present invention can be implemented as a n-phase system, for any n. To illustrate this point, a 1-phase system, 1000, is illustrated in Figure IB. When comparing Figures 1 and IB, in Figure IB, two of the incoming phases have been eliminated. The blocks, functionally, and the labels are all the same in another way. The only difference between a one-phase system and a two or more phase system is that the 22-30 switches are only able to connect or disconnect their respective branch circuits to the one phase, and not to change the circuit connection derived from a phase to a different phase. Thus in a one-phase system, the only option in the case of an overloaded system is to choose which branch circuit is disconnected, not choose which phase the branch circuit will reconnect to. Thus the present invention applies to energy sources of any number of phases, although the usual cases are those of 3 phases and 1 phase, as s illustrated in Figures 1 and IB, respectively.
A second example of the present invention, illustrated in Figure 2, functions to uniformly distribute the load through each of the phases of a three-phase power distribution network, each of the phases, fl, f2, f3 , from a three-phase power distribution network is input to an electric power adding circuit 52. The additive circuit 52 functions to receive each incoming phase and combine its current and power handling capacity and subsequently form a single added output. The output of the adder circuit 52 is a single AC electrical voltage having a current capacity approximately equal to the sum of the current capacities of the three incoming phases.
The output of the adding circuit 52 is subsequently input to a rectifier 54. The rectifier 54 rectifies the output of A of the adding circuit 54 to an essentially CD level. The carrying capacity of the rectifier 54 must be sufficient to handle the total current requirements of all combined branch circuits that must be covered by the device 10.
The output of the rectifier 54 is input to an AC 56 generator. The generator of CA 56 produces a single-phase AC voltage from the DC voltage output of the rectifier 54. The appropriate voltage and frequency (eg, 120 V 60 Hz for the United States) is generated for the device 10 of the particular locality in which you must operate.
The output of the AC generator 56 is introduced to branch circuit breakers 32, 34, 36, 38, 40, covered by the device 10. The branch circuits are supplied with energy by the output of the branch circuit breakers 32, 34, 36, 38, 40. Although five branch circuits are illustrated in Figure 2, any number of branches can be covered by device 10, provided that the components have sufficient current calibration for the combined load of all branch circuits.
The actual load distribution in device 10 occurs in the adding circuit 52. Regardless of how the load in each branch circuit increases or decreases, it is automatically distributed evenly through the three incoming phases. For example, if the load in any derivative or group of derivatives increases by 30%, the corresponding load in each incoming phase increases by 10%. Since each of the incoming phases can be represented by a source of low equivalent impedance of current that are identical to each other, if the load in the additive circuit 52 is increased by 30% then this increase appears in the same way through of each of the three incoming phases.
The advantage of this second example over the first example is that it is less complex, however, it is possibly more expensive due to the expensive components that must be used for the adder circuit 52, the rectifier 54 and the AC generator 56 that with able to handle the increased current levels.
Figure 2B shows a simple implementation of the additive circuit, rectifier 54 of Figure 2, which combines the two functions in a block, three-phase rectifier, 524. Figure 2B also shows the optional filter capacitor 58.
It is important to note that the system in Figures 2 and 2B is not an uninterruptible power supply battery backup system, but rather provides load balancing due to the single phase output circuit, likewise, in all three phases input, by the use of the add-on circuit 52. The presence of the add-on circuit 52 results in the load of the single-phase output circuit being instantaneously shared in substantially equal fashion through the three phases of the incoming three-phase power circuit , even they are the load balancing processor 12 of Figure 1. Hence, the system of Figure 2 and 2B provides an improvement in the performance of the system of the present invention on the implementation of Figure 1.
Thus, an energy distribution system such as the battery backup system of the prior art presented by Fiorina in U.S. Patent No. 5,477,091, which is a fully e-phase system, which includes backup battery, can not do obviates the load balancing function achieved by the implementation of Figure 2 and 2B of the present invention.
Furthermore, the AC generator 56 can be realized as a "stationary converter" - a DC to AC convertor or CD to AC inverter, without departing from the teaching of the present invention, as an "AC generator" is just a "rotary converter". Thus a stationary converter could also be used as is well known. A schematic example of a "stationary inverter" inverter CD to AC is given in Figure 2C. The introduction of CD 213 of the additive rectifier 524 energizes inverter CD to CA 200, which provides square wave AC output 211, which, after optional low pass filtering by inductors 208 and 209 and capacitor 210, is return sinusoidal AC output 212. The given exemplary circuit is a free push-pull oscillator, consisting of a pair of transistors with switches 201 and 202, the pickers of which are connected to the ends of the primary winding 207a, of the saturated core transformer , 207. The CD input is applied from the central cover of the primary connection to the common one of the emitters 201 and 202. The forward pulse is applied to the transistors 201 and 202 by the resistors 203 and 304, respectively, which are ignored by CA through capacitors 205 and 206, respectively. The feedback is coupled by a transformer winding 207c to the base of the transistor 201 and by winding the transformer 207d. to the base of transistor 202. The oscillator is free at a frequency that depends on the design of the saturated transformer. The above is a crude implementation of this type of circuit, and is given by way of example, to illustrate the principle of the operation. This is known as an Oscillator Royer, for the inventor. The circuit was published in Royer, G.H., an AC to DC converter with a switch transistor, Trans AIEE, July 1955.
Improved designs, such as an inverter 2000 in Figure 2D, use an unsaturated transformer for 207 and add a 2070 saturating feedback transformer to the base circuits. The base saturation feedback transformer then determines the operating frequency of the inverter CD to AC. This circuit does not provide regulation of the output voltage. In both circuits, the maximum to maximum voltage of the secondary square wave output depends on the input of voltage, and the output frequency depends on the input DC voltage as well as the characteristics of the saturating transformer. This improved inverter was published in Jensen, J.L., An improved square wave oscillator circuit. Trans. IRÉ, volume CT-4, number 3, September 1957.
The system of Figure 2, then, can be implemented inexpensively by combining the three-phase rectifier of Figure 2B with an inverter like that of Figure 2C or 2D. The three-phase rectifier balances the loads equally through each of the three input phases without any required computer equipment.
The system of Figures 2, 2B and 2C or 2D, can equally well be applied to a two-phase system, or to a system of more than three phases, that is, to an n-phase power distribution system. Filter capacitor 58, and low pass filter 208, 209 and 210 may optionally be included, to provide sine wave output, 212, depending on the output spectrum required by the load circuit to be delivered.
The system in Figure 2, 2B, 2C is especially appropriate for small-scale installations, say, an individual factory. In this case the use of this implementation of the present invention will be useful in reducing the problem of correction of the energy factor in the entrance of the site, since all the various motor loads, and other loads not purely resistant, will have been removed from the AC power input to this site, and will have been replaced by an "input rectifier" circuit. It is possible, that with the omission of capacitor 58, or the use of a very small capacitivity for noise filtering only, that the inductance of primary 207a of transformer 207, which will appear inductive, will present an improved power factor over that of a installation are this current load balancing circuit. The above is because the capacitor input rectifier provides an energy factor of around 0.6, while an "infinite inductor" rectifier circuit ideally provides an energy factor of around ninety percent.
The improved form of the CD to AC inverter of Figure 2D, with a non-saturating collector transformer for 207, and with a separate saturating base transformer 2070, will provide even greater improvement in the site input energy factor. Finally, a third variation is a "current-fed" push-pull converter, in which a large inductor is added in series with the DC supply input connection to the transformer 207 center cover. The foregoing would provide greater inductance in the circuit rectifier, also increasing the input energy factor. A high energy factor near the unit is important for energy companies, since this represents possible savings in the cost of energy distribution facilities, as is well known. Figure 2E shows the system 10, which includes the three-phase rectifier 524, and a CD-to-AC inverter "stationary converter" 200, with inductor 2071, added to increase the input power factor. A purely resistive load has an energy factor of 1.0. The phase change of load current due to non-resistive loads, and the distortion due to non-linear loads, reduce the energy factor and result in higher installation costs to the electric company, due to an inefficient coupling of electrical energy to the consumer loading site.
While stationary inverter circuits are very old technology, they represent the simplest and least expensive implementation. The newer pushbutton switch regulators, which incorporate feedback control circuits, and without saturating transformers can be used to implement stationary inverters having voltage and output frequency independent of the input voltage. The implementation of said inverters when operating from low voltage battery supplies is well known. The design of said circuits for higher input voltage is direct, less difficult than the case of low voltage input.
Figure 2F replaces the inductor 2071 of Figure 2E by a high power factor d controller increase switch controller 5242, to further increase the input power factor. The 5242 magnification regulator can employ a high power factor controller such as parts number UC1854 of Unitrode Integrated Circuits Corporation, this part and its application is well documented in the Unitrode literature, which can be found in the Product Manual and Applications '93 -'94, # IC850, Unitrode Integrated Circuits Corporation, 7 Continental Boulevard, Merrimack, New Hampshire, United States of America 03054. Phone: (603) 424-2410, Fax: (603) 424-3460. Block 5242 provides a regulated DC output voltage 5244 to the DC to AC 5242 inverter, which removes a cause of variations in AC output frequency, as well as repairs the output amplitude of the DC to AC converter 10. The resistor of capacitor 5243 , provides a load storage, which allows the inverter DC to AC 10 continue to provide an output of AC 211, for a few milliseconds after any voltage condition in the transient input line. The foregoing provides some immunity to small "faults" and provides time to orderly shut down loads, if a low input voltage warning signal is provided by the 5242 boost controller, as is often done. The UC1854 and similar high-power factor controllers are capable of providing input power factors to an n-phase power source, greater than 0.88 when working in a normal single-phase system. With a three-phase input as illustrated in Figure 2F, the identical circuit should provide a higher input power factor, since the source of the error known as "cusp distortion", described in the Unitrode literature, should not be present when uses the controller with an n-phase power source. The above is because the additional phases do not allow the minimum input voltage to the gain regulator with high power factor to momentarily drop to zero, as with a full-wave bridge rectifier of a phase, for example, since the additional phases fill the "gap" between the two half cycles of the input of a phase. The cusp distortion is analogous to the cross-distortion in the amplifiers, and is removed by filling in the ripple waveform, since the input voltage does not instantaneously reach the low input voltage range of almost zero volts.
The power factor controller 1854 and the design procedure 30 are described in the following Unitrobe IC Corporation literature: (1) UC 1854/2854/3854 High Power Factor Pre-regulator (data sheet) 1854). (2) U-134, UC3854 Design of correction circuit of the controlled energy factor. • (3) DN-39D, Performance optimization in UC3854, Energy factor correction applications. (4) DN-41, Extended current transformer ranges. (5) U-140, Control of average current mode of interrupted power supplies.
In summary, the method of the system of Figures 2, etc. to uniformly balance the electric charge in a n-phase electric power source includes the steps of: rectifying said n-phase power source to produce a DC voltage source; connecting said DC voltage source to a DC to AC inverter, to generate an output voltage AC; generating said AC output voltage from said DC voltage; connecting the AC loads to said AC output voltage, so as to provide an output AC load current to said AC loads; whereby said outgoing AC load current is reflected back through said CD to AC inverter as a DC load current in said DC voltage source, and therefore said CD load current in turn it is reflected back through said n-phase rectifier as an input AC load current in said n-phase power source, said input AC load current is also provided by said n phases of said power source of n phases by means of said n-phase rectifier, thus said output current load AC is balanced equally in said n phases of said n-phase power source.
Figure 3 is a block diagram of an example of the present invention, which combines the characteristics of the systems of Figures IB and 2F, and which also adds the communication capacity, for example, with the electric company or with the consumer , via a communication link, for example, a modem 3001. The implementation of the system of Figure 2F is inserted between the circuit breaker of company 14 of Figure IB and the rest of the system of Figure IB, which provides a rolling of automatic loads, and also a high energy factor, as described above. The system of Figure IB is represented here as n units of circuits labeled 1001 ... 1002, which represent each of the units of the circuit related to each of the m derived circuits. These "units" m derived circuits are connected to the processor 3012 as well as the processor 12 in Figure IB, and are not controlled only in the same way as the processor 3012, to limit the maximum loads in the n-phase company circuit. by limiting the maximum charge current provided by the DC to AC inverter 10, but the processor 3012 has additional capabilities as will be described. Now, the modem 3001 is connected by bilateral data bus 3004, to the processor 12. The modem 3001 is preferably connected via an RJ11 interface 3002 to the telephone line of the head office 3003. This modem 3001 provides the communication capability, for example, with the electric company or with the consumer.
In addition to the control preprogrammed by the processor 12 of the connection and disconnection of loads, that is to say, branch circuits, in response to the measurements of currents carried out by the sensors, 18 and 42m, the processor 3012 also accepts the preprogramming to control the addition or decrease of charges as a function of time, for example, hour.of the day or day of the week. Also the descent of the loads in the case of an overload condition in the power line, and the reconnection of the loads, can be carried out according to the priorities preprogrammed by the consumer in the processor 3012. Thus, the consumer of Electric power can exert control over the operation of the equipment in its location, even in its absence. In addition, the processor 3012 can report data to the electricity company, communication via modem 3001.
Additionally, the power company may perform processor inquisitions, for example, related to the loads of each of the phases in an n-phase system such as that in Figure * 1, or the loads of each branch circuit, in any of the implementations illustrated in the figures, also, the electric company or the consumer can issue commands to the processor, for example, connect or disconnect loads, therefore exerting control over the loads in the consumer installation via the modem 3001 and the processor 3012, and the utility or the consumer can remotely reprogram the 3012 processor via the 3001 modem. While a wired telephone line connection is illustrated, the use of a cellular telephone, or other method of wireless communication to perform the communication link with the processor 3012 is likewise included within the scope of the invention.
Figure 4 shows an alternative implementation 5400 of the combination of blocks 52 and 54 of Figure 2, for a three-phase system, such as an example of an n-phase system, with n = 3. In Figure 4, each of the phases is first rectified in the rectifiers 401-403 with each of the outputs of the rectifiers serving as the input to a separate energy factor correction module (PFC) 405-407, as it is discussed before, for example, using a UC1854 controller or similar. The outputs of the n power factor correction modules are connected together, and to the lift capacitor 409, which provides a DC output 410. The n PFC modules have a common shared load bus interconnection 408 as presented in FIG. Literature Unitrode with respect to its UC1907 Shared Side Controller shared circuit, for example, and with respect to the interrupt regulator controllers, as is the UC1842. The purpose of the shared load bus is to ensure that each of the PFC modules provides an equal share of the load current as each of the other PFC modules, more or less with a tolerance of, say, 10% or less.
The advantage of the implementation of Figure 4 over that of Figures 2 and 2B is that the implementation of Figure 4 provides with greater certainty at the same time improved roll of the charges in the n phases and improved energy factor in each of them. the n phases.
Figure 5 shows the additional connection of an additional electric meter 5001 to a processor 3012, as is a processor 3012 of Figure 3. The digital electric meter 5001 is a digital kilowatt hour meter, which records the consumption of electrical energy cumulative. The processor 3012 has the associated connection 3004 to the modem 3001, which is preferably connected via an interface 3002 to the telephone line of the head office 3003. With this arrangement, the use of the electric power of the consumer's facility is made available to through the processor and the communication link for the transmission of a requesting location, for example, the electric power company.
In another example, implicitly included in Figure 3, the current sensors 18 and 42n are continuously monitored by the processor 3012 and in conjunction with the simultaneous measurements of voltage at the current sensor positions, the instantaneous energy consumption it can be calculated as is well known, and it can be added continuously, "integrated", in the 3012 processor, in order to maintain the cumulative electrical consumption of the installation. The equipment needed for each energy measurement is illustrated in Figure 5B, which shows current sensor 518 with output 5181 to processor 3012 and voltage sensor 5189 with output 5189V to processor 3012. Thus the functionality of the digital energy meter 5001 can be incorporated into the system of the Figure 3, and similarly in a n-phase system, as in Figure 1.
The function of the digital electric meter, whether implemented as a discrete instrument as in Figure 5, or implicitly in Figure 3 as described above, can be useful in any of the systems described herein, even without a communication link, for provide an additional parameter for use in the handling of loads.
While the invention has been described with respect to a limited number of copies, it will be appreciated that many variations, modifications and other applications of the invention can be made, In particular, the usual case of n phases of n = 3 has been used as An example. In general, the number of phases is not limited to three phases, but can be any number of phases. In addition, any form of communication link can be used for the exchange of information between the processor at the location of the consumer and the electric company.

Claims (10)

  1. CLAIMS: 1. A three-phase load distribution system for uniformly distributing an electrical load, present in a plurality of branch circuits, through a three-phase power distribution network, comprising: a first, second and third sensor current coupled to a first, second and third phase, respectively, of the three-phase electrical power distribution network, said first, second and third current sensors for measuring the flow of electrical energy through said first, second and third phase, respectively; a plurality of switches, each of said switches coupled to one of the plurality of branch circuits, each of said plurality of switches for connecting any of said first, second and third phase to one of the plurality of branch circuits; a plurality of current sensors for measuring the electric currents flowing through each of said plurality of branch circuits; each of said current sensors coupled to one of said plurality of branch circuits; and a processor coupled to said first, second and third sensors, said plurality of switches and said plurality of current sensors; said processor for calculating (a) the differences between said electric currents flowing through each of the pairs of said first, second and third phases; and (b) the rhythms of said electric currents flowing through each pair of said first, second and third phases; said processor for controlling said plurality of switches so that a function chosen from the group consisting of 8a) the differences between, and (b) the proportions of said electric currents flowing through each pair of said first, second and third phases do not exceed a predetermined threshold; said processor calculates alternative combinations of derivatives to be connected by said switches to said phases, and said processor controls the reconnection of said derivatives by means of said switches so that said functions do not exceed said threshold.
  2. 2. A load distribution system in at least one phase for uniformly distributing an electric charge, present in a plurality of branch circuits, through an energy distribution network of at least one phase, comprising: at least one sensor current coupled to at least one phase, respectively, of the electric power distribution network of the at least one phase, said at least one current sensor for measuring the electric currents flowing through said at least one phase, respectively; a plurality of switches, each of said switches coupled to one of the plurality of branch circuits, each of said plurality of switches for connecting any one of said at least one phase to one of the plurality of branch circuits; a plurality of current sensors for measuring the electric currents flowing through each of said plurality of branch circuits; each of said current sensors coupled to one of said plurality of branch circuits; and a processor coupled to said first, second and third current sensors, said plurality of switches and said plurality of current sensors; said processor for calculating, (a) the differences between said electric currents flowing through each of the pairs of said first, second and third phases; and (b) the rhythms of said electric currents flowing through each pair of said first, second and third phases; said processor for controlling said plurality of switches so that a function chosen from the group consisting of (a) the differences between, and (b) the proportions of said electric currents flowing through each pair of said first, second and third phases does not exceed a predetermined threshold; said processor calculates alternative combinations of derivatives to be connected by said switches to said phases, and said processor controls the reconnection of said derivatives by means of said switches so that said functions do not exceed said threshold.
  3. 3. A three-phase load distribution system for uniformly distributing an electric load, present in a plurality of branch circuits, through a three-phase power distribution network, comprising: a first, second and third current sensor coupled to a first, second and third phase, respectively, of the three-phase electric power distribution network, said first, second and third current sensors for measuring the electric currents flowing through said first, second and third phase, respectively; first, second and third circuit breakers coupled to said first, second and third phases, respectively; a plurality of switches, each of said switches coupled to one of the plurality of branch circuits, each of said plurality of switches for connecting any of said first, second and third phases to one of the plurality of branch circuits; a plurality of circuit breakers, each coupled to one of the plurality of branch circuits; a plurality of current sensors for measuring the electric currents flowing through each of said plurality of branch circuits; each of said current sensors coupled to one of said plurality of branch circuits; a processor for controlling said plurality of switches so that said electric currents flowing through each of said first, second and third phases does not exceed a predetermined threshold; said processor coupled to said first, second and third current sensors, said plurality of switches and said plurality of current sensors; and a communication link connected to said processor to provide communications capability.
  4. 4. The system of Claim 1, further comprising a communications link connected to said processor to provide communications capability.
  5. 5. The system of Claim 2, further comprising a communications link connected to said processor to provide communications capability.
  6. 6. A three-phase load distribution system for uniformly distributing an electrical load, present in a plurality of branch circuits, through a three-phase power distribution network, comprising: a first, second and third current sensor coupled to a first , second and third phase, respectively, of the three-phase electrical power distribution network, said first, second and third current sensors for measuring the electric currents flowing through said first, second and third phase, respectively; a plurality of switches for receiving and decoding the corresponding control signals, each of said switches coupled to one of the plurality of branch circuits, each of said plurality of switches for connecting any of said first, second and third phases to one of the plurality of derived circuits; a plurality of current sensors for measuring the electric currents flowing through each of said plurality of branch circuits; each of said current sensors coupled to one of said plurality of branch circuits; a processor for controlling said plurality of switches so that said electric currents flowing through each of said first, second and third phases does not exceed a predetermined threshold; said processor coupled to said first, second and third current sensors, said plurality of switches and said plurality of current sensors; and a communication link connected to said processor to provide communication capability, which further comprises a digital energy measurement function, said digital energy meter includes the ability to measure energy; said digital energy meter is chosen from the group consisting of (a) a kilowatt meter per digital hour to record the cumulative electric power consumption; and (b) a combination of a voltage sensor with one of said sensors, said voltage and current sensors have outputs to said processor to calculate a measurement related to the energy chosen from the group consisting of instantaneous energy consumption and consumption of energy. cumulative electric power, said energy measurement function to provide an additional parameter for use in the handling of loads; and said energy measurement function for providing electrical power usage of a consumer facility via a communication link.
  7. 7. A system as in Claim 3, further comprising a digital energy measurement function, said (a) a kilowatt meter per digital hour for recording cumulative electrical power consumption; and (b) a combination of a voltage sensor with one of said sensors, said voltage and current sensors have outputs to said processor to calculate a measurement related to the energy chosen from the group consisting of instantaneous energy consumption and consumption. of cumulative electric power, said energy measurement function to provide an additional parameter for use in the handling of loads; and said power measurement function for proportional- electric power use of a consumer facility via a communication link.
  8. 8. The system of Claim 1, further comprising a digital energy measurement function that includes the ability to measure energy, said digital energy meter chosen from the group consisting of: (a) a kilowatt meter per digital hour to record the cumulative electric power consumption; and (b) a combination of a voltage sensor with one of said sensors, said voltage and current sensors have outputs to said processor to calculate a measurement related to the energy chosen from the group consisting of instantaneous energy consumption and consumption of energy. cumulative electric energy, said energy measurement function to provide an additional parameter for use in the handling of loads. said energy metering function for providing electric power usage of a consumer facility via a communication link.
  9. 9. A load distribution system in at least one phase for uniformly distributing an electric charge, present in a plurality of branch circuits, through an energy distribution network of at least one phase, comprising: at least one sensor current coupled to at least one phase, respectively, of the electric power distribution network of the at least one phase, said at least one current sensor for measuring the electric currents flowing through said at least one phase, respectively; a plurality of switches for receiving and decoding the corresponding control signals, each of said switches coupled to one of the plurality of branch circuits, each of said plurality of switches for connecting any one of said at least one phase to one of the plurality of derived circuits; a plurality of current sensors for measuring the electric currents flowing through each of said plurality of branch circuits; each of said current sensors coupled to one of said plurality of branch circuits; and a processor for controlling said plurality of switches so that said electric currents flowing through said at least one phase do not exceed a predetermined threshold, said processor coupled to said at least one current sensor, said plurality of switches and said plurality. of current sensors, which further comprises a digital energy measurement function, said digital energy meter chosen from the group consisting of: (a) a kilowatt meter per digital hour to record the accumulative power supply, and (b) ) a combination of a voltage sensor with one of said sensors, said voltage and current sensors have outputs to said processor to calculate a measurement related to the energy chosen from the group consisting of instantaneous energy consumption and cumulative electric power consumption , said energy measurement function to provide an additional parameter for use in the handling of loads.
  10. 10. The system of Claim 2, further comprising a digital energy measurement function, said digital energy meter chosen from the group consisting of: (a) a kilowatt meter per digital hour for recording cumulative electrical power consumption; and (b) a combination of a voltage sensor with one of said sensors, said voltage and current sensors have outputs to said processor to calculate a measurement related to the energy chosen from the group consisting of instantaneous energy consumption and consumption of energy. cumulative electric energy, said energy measurement function to provide an additional parameter for use in the handling of loads. EXTRACT OF THE INVENTION An apparatus and a method for uniformly distributing an electric charge through a power distribution network in phase n. The current in each incoming phase (fl, f2, and f3) and in each branch circuit (1-5) is measured by a current sensor (16, 18, 20, 42, 44, 46, 48 and 50). The outputs of the current sensors are monitored by a processor (12). Related to each of the branch circuits there is a multipolar switch (22, 24, 26, 28 and 30) and a conventional circuit breaker (32, 34, 36, 38, 40). Each switch (22, 24, 26, 28 and 30) is able to connect its corresponding branch circuit (1-5) to any incoming phase (fl, f2, and f3) and to disconnect the branch circuit (1-5) from all phases n (fl, f2, and f3). The processor 12 periodically monitors the current flowing through each incoming phase and, based on the conditions of the branch circuit loads (1-5), reprograms the switches (22, 24 and 26) to maintain the circuit loads branch (1-5) evenly distributed in all incoming phases (fl, f2, and f3).
MXPA/A/1999/005035A 1999-05-31 MXPA99005035A (en)

Publications (1)

Publication Number Publication Date
MXPA99005035A true MXPA99005035A (en) 2000-09-04

Family

ID=

Similar Documents

Publication Publication Date Title
US6018203A (en) Apparatus for and method of evenly distributing an electrical load across an n-phase power distribution network
AU711943B2 (en) Apparatus for and method of evenly distributing an electrical load across a three-phase power distribution network
Gwon et al. Mitigation of voltage unbalance by using static load transfer switch in bipolar low voltage DC distribution system
CN109921445B (en) Transformer area phase change switch control method considering branch line power balance
US11901810B2 (en) Adaptive electrical power distribution panel
JP2000228826A (en) Power supply device according to quality
Bettanin et al. Voltage management strategies for low voltage networks supplied through phase-decoupled on-load-tap-changer transformers
Ramamurthy et al. Mitigation of motor starting voltage sags using distribution-class statcom
WO2018060129A1 (en) A power converter system for power quality compensation and load balancing connected to an electric power distribution grid
Kumar A Review of Power Quality Problems, Standards and Solutions
MXPA99005035A (en)
Mirzadeh et al. Power hardware-in-the-loop verification of a cold load pickup scenario for a bottom-up black start of an inverter-dominated microgrid
Ogunyemi et al. Investigation of voltage unbalance in a distribution network: A case study of federal polytechnic Ilaro
KR20200104067A (en) Smart power switching method and system
RU2353046C1 (en) Ac power supply unit
CZ203899A3 (en) Method of uniform distribution of electric loading via n-phase distribution network and apparatus for making the same
CN115833146A (en) Mobile single-phase motor compensation device
Thit et al. Performances Analysis on Power Quality Problems Mitigation by using Unified Power Quality Conditioner (UPQC)
CN115085226A (en) Unbalanced three-phase treatment equipment in platform district
CN115085225A (en) Transformer area three-phase imbalance management and open capacity calculation method
WO2023129422A1 (en) Microinverter for use with storage system
IL119435A (en) Apparatus for and method of evenly distributing anelectrical load across a three phase power distri bution network