Classifications

• • 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
  • H02M5/00—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases
  • H02M5/02—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC
  • H02M5/04—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC by static converters
  • H02M5/10—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC by static converters using transformers
  • H02M5/12—Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases without intermediate conversion into DC by static converters using transformers for conversion of voltage or current amplitude only
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J13/00—Circuit arrangements for providing remote monitoring or remote control of equipment in a power distribution network
  • H02J13/12—Monitoring network conditions, e.g. electrical magnitudes or operational status
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/12—Arrangements for adjusting voltage in AC networks by changing a characteristic of the network load
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
  • H02J3/1807—Arrangements for adjusting, eliminating or compensating reactive power in networks using series compensators, e.g. thyristor-controlled series capacitors [TCSC]
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02J—ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
  • H02J3/00—Circuit arrangements for AC mains or AC distribution networks
  • H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
  • H02J3/1878—Arrangements for adjusting, eliminating or compensating reactive power in networks using tap changing or phase shifting transformers
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P13/00—Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output
  • H02P13/06—Arrangements for controlling transformers, reactors or choke coils, for the purpose of obtaining a desired output by tap-changing; by rearranging interconnections of windings
• • 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
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
  • Y02E40/30—Reactive power compensation
• • 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
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
  • Y02E40/70—Smart grids as climate change mitigation technology in the energy generation sector
• • 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
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• • 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
  • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
  • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
  • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
  • Y04S10/22—Flexible AC transmission systems [FACTS] or power factor or reactive power compensating or correcting units
• • 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
  • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
  • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
  • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
  • Y04S10/30—State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge

Definitions

• the present invention relates to a device for adjusting the voltage of electrical networks.
• the present invention relates more particularly to a device for dynamic adjustment of the voltage which is intended to equip electrical networks and which comprises a first voltage electrical network having a determined number of phases and a second voltage electrical network. Such networks are connected to each other by a distribution transformer thus making it possible to modify a voltage U1 of the first voltage electrical network.
• a device for dynamic adjustment of the voltage which is intended to equip electrical networks and which comprises a first voltage electrical network having a determined number of phases and a second voltage electrical network.
• Such networks are connected to each other by a distribution transformer thus making it possible to modify a voltage U1 of the first voltage electrical network.
• a medium-voltage / low-voltage distribution transformer used on state-of-the-art electrical distribution networks prior to the invention is a generally three-phase voltage-lowering transformer.
• the power source is located upstream of the medium-voltage network, the powered loads are located downstream of the low-voltage network powered by the same transformer.
• compound voltage is the potential difference between two conductors of different phases in a polyphase system.
• the voltage delivered to these loads must respect a contractual voltage of 400 V per year. example, within a tolerance of +/- 10%.
• the tolerance on the medium voltage network is also +/- 10%.
• the conventional transformer comprises a static adjustment device for adjusting in a standard manner its transformation ratio according to these voltage drops.
• a device whose primary (medium-voltage) and secondary (low-voltage) voltages are respectively 20 000 V and 400 V will offer the possibility of choosing between 5 reports, ie: 19000/400 V (-5 %), 19500/400 V (-2.5%), 20 000/400 V (0), 20500/400 V (+ 2.5%) or 21000/400 V (+5%).
• This static adjustment device consists of a three-phase switch connected to different jacks made at the medium-voltage windings of the transformer and to vary the number of active turns within these windings.
• the switch can only be operated in the absence of voltage, therefore only before the transformer is put into service.
• decentralized energy production sources for example photovoltaic power plants installed in single-family dwellings and more particularly connected to low-voltage public distribution networks
• these decentralized sources operate randomly depending on weather conditions. It follows that the energy flow through the medium-voltage / low-voltage transformer, which feeds the low-voltage network to which these production sources are connected, can pass from the medium-voltage to the low-voltage, or conversely, from low voltage to medium voltage. It is then necessary to compensate differently for the internal voltage drop of the distribution transformer, as well as the voltage drops due to the networks, according to the direction of the energy flow and therefore dynamically and not lump-sum. The static adjustment device mentioned above is therefore no longer suitable for these new operating conditions.
• Load voltage regulators for power transformers are available on the market. Such a device is described, for example, in DE 10 2008 027 274. This patent describes complex and expensive systems, requiring periodic maintenance, reserved for high-power transformers, which makes their use unthinkable together with medium distribution transformers. -tension / low-voltage. Indeed, the large number of these reduced power transformers on the public electricity distribution networks implies the choice of economic solutions and do not require regular maintenance.
• patent application DE 10 2009 014 243 A1 presents a solution for dynamically adjusting the voltage from an autotransformer connected to a secondary winding of the distribution transformer and having different taps on this winding.
• the voltage adjustment is made by switching from one outlet to another by means of thyristor switching.
• the advantage of this type of switching is to avoid the dead time during the passage between two consecutive holds, corresponding to an interruption that would cause a disruption of the distribution of energy.
• the electronic control allows a cutoff at the initial setting and a closing at the desired take that are perfectly simultaneous.
• the system as a whole consisting mainly of electronic components, has a lifetime and reliability vis-à-vis operating constraints that make it globally unlikely to be compatible with public distribution networks. Indeed, the life of such a system is of the order of 15 years, where power electrotechnical equipment, such as transformers of distribution, are operated without maintenance for more than 30 years. In addition, these devices must be able to withstand overvoltages of the order of ten kilovolts, as well as overload or short-circuit currents of several kiloamperes generating significant adiabatic heating, to which the solutions based on the use of thyristors are not suitable.
• the objective of the present invention is to provide a voltage adjusting device, this device being associated with the distribution transformer, that is to say located nearby in a specific envelope, or integrated in the envelope of the distribution transformer itself, and to compensate for voltage drops dynamically and not lump sum, in a simple and economical way, and without the need for regular maintenance.
• This device uses conventional switching means while avoiding disturbances during the switching phases. It is also adapted to operating constraints specific to medium-voltage / low-voltage distribution networks and does not cause significant energy losses in comparison with those of the distribution transformer with which it is associated.
• the device of the invention is essentially such that it comprises a control transformer whose number of phases is identical to that of the first voltage network, the regulating transformer comprising, for each phase of the first voltage network, a secondary winding connected in series with the first voltage network and a primary winding of which a variable number of turns is connected to the second voltage network so as to obtain at the terminals of the secondary winding a voltage U3 chosen to be added to the voltage U1 of the first voltage network, to adjust a voltage U2 of said second voltage network.
• the adjustment device comprises as many single-phase control transformers as the first voltage network comprises phases.
• the primary winding comprises jacks arranged along its length so that the variability of the number of turns connected to the second voltage network is obtained, the jacks being connected or disconnected from the second network. voltage by means of switching members of the adjusting device.
• the various switching members are actuated in a logical order defined by a truth table stored in a control interface of the adjustment device.
• the first voltage electrical network being polyphase, it comprises, for each phase, a tertiary winding said stabilization positioned parallel to the other two windings and in the immediate vicinity of the secondary winding, each tertiary winding d a phase being coupled in series with the tertiary windings of the other phases.
• the switching members specific to each phase of the first voltage electrical network are operable independently of those connected to the other phases and voluntarily non-simultaneous.
• the primary winding comprises two inputs which can be connected independently of one another to a first phase or a second phase of the second voltage network.
• the first voltage network is a medium-voltage network and the second voltage network is a low-voltage network
• the distribution transformer is a medium-voltage / low-voltage distribution transformer .
• the adjustment transformer of the adjustment device is integrated in the distribution transformer.
• the various switching members are controlled by the control interface on receipt of and according to information conveyed by means of an electrical or optical signal and supplied to the control device by an information exchange device with a network manager.
• the information is representative of the voltages composed of the first voltage network, measured between the secondary windings of the control transformer and the distribution transformer.
• the information is a combination of the components. vectors of the compound voltages U2 of the low-voltage network and the vector components of the currents 12 flowing in the different phases of the low-voltage network.
• FIG. 1 represents a single-wire electrical diagram of a first voltage network, having a rated voltage U1, and a second voltage network, having a rated voltage U2, these networks being connected to each other by a distribution transformer and a device dynamic voltage regulation according to the present invention.
• FIG. 2 represents a single-wire electrical diagram of the device for dynamically adjusting the voltage according to a first embodiment.
• FIG. 3 shows an alternative embodiment of the device for dynamically adjusting the voltage illustrated in FIG. 2.
• FIG. 4a represents a truth table containing the choice and order of tilting of cut-off members of the device for dynamic adjustment of the voltage according to its variant embodiment illustrated in FIG. 4b.
• FIG. 4b represents an alternative embodiment of the device for dynamically adjusting the voltage illustrated in FIG. 3 which comprises a control interface.
• FIG. 5 represents a diagram of a three-phase system comprising, on each phase of the dynamic voltage control device according to this embodiment of the invention, a tertiary stabilization winding in addition to the primary and secondary windings.
• FIG. 1 shows in a single-wire fashion an electrical distribution system comprising a first voltage network 1 having a rated voltage U1 and a second voltage network 2 having a rated voltage U2. These networks are connected to each other at least by one Distribution transformer 5.
• the distribution transformer 5 is connected to the first voltage network 1 by means of a voltage adjusting device 3. The latter introduced between the input and output of the distribution transformer 5 a voltage U3 variable and selected. Between the device 3 and the first distribution transformer 5 is located a first electrical connection 6.
• the adjustment device 3 takes the necessary power at the outputs of the distribution transformer 5 connected to the second voltage network 2 by the intermediate of a second electrical connection 4.
• the adjustment device 3 is located between the distribution transformer 5 and the second voltage network 2.
• the device comprises only elements subjected to a low voltage.
• the intensities transited are high.
• the networks 1 and 2 are respectively medium and low-voltage networks.
• these networks may have a destination other than that of the public distribution of electrical energy. Their respective voltage may lie in a field other than those of the medium-voltage or the low-voltage.
• FIG. 2 shows the single-wire electrical diagram of the adjustment device 3 according to a first embodiment.
• the adjustment device 3 comprises a regulating transformer 7 whose number of phases is adapted to that of the distribution transformer 5.
• a primary winding 8 of the regulating transformer 7 is connected to the low-voltage network 2 via the second electrical connection 4 consisting of phases 4a and 4b.
• this primary winding 8 comprises setting taps 9 separated from each other by a defined number of turns, and capable of being connected to the link 4b via switching members 10a, 10b , 10c, 10d, which are typically low-voltage contactors.
• the number of sockets 9a, 9b, 9c, 9d and switching members 10a, 10b, 10c, 10d depends on the number of desired adjustment steps, which in this example is equal to 4.
• a secondary winding 1 1 of the regulating transformer 7 is connected in series between the first voltage network 1 and the electrical connection 6 supplying the distribution transformer 5.
• the control transformer 7 is dimensioned so as to generate, across its secondary winding 11, a potential difference U3 equal, for example, to 2.5%, 5%, 7.5%, 10% of the single voltage of the network 1 depending on whether the socket 9a, 9b, 9c or 9d is connected to the phase 4a via a cut-off member 10a, 10b, 10c or 10d in the closed position.
• This member may be unipolar or on the contrary have as many poles that the adjustment device 3 comprises phases.
• the voltage U3 can be made equal to 0 by short-circuiting the two inputs of the winding 8 by means of an additional cut-off member 12 which is here a bipolar contactor. This provides a setting range from 0 to + 10% in steps of 2.5% with 4 shots. But this range, as well as the importance of the steps of adjustment, can be chosen differently according to the needs, by adapting the number 9a, 9b, 9c, 9d and the number of turns of the primary winding 8 which separate them.
• the tap change is done simultaneously on each phase of the system to maintain a balance of voltages.
• the cut-off devices 10a, 10b, 10c, 10d and 12 may for example be three-phase contactors.
• Figure 3 shows a variant with respect to Figure 2 for reducing the overall power of the system for an equivalent effect.
• a setting range of the voltage ranging from 0 to 10% assumes a power of the adjustment device 3 as described in Figure 2 equal to 10% of the power of the distribution transformer 5.
• the principle shown in the figure 3 allows to reduce by half this power while maintaining the same amplitude of adjustment.
• This advantage is obtained from the possibility of reversing the phases 4a and 4b supplying the two inputs 15 and 16 of the primary winding 8 of the control transformer 7.
• the voltage U3 appearing across the winding secondary 1 1 can be added to or subtracted from the voltage of the first voltage network 1.
• a setting range of 10% can therefore be covered by a device having a range of 5%, for example with 3 positions 0, + 2.5%, + 5%, which according to the order of the phases 4a and 4b supplying the 8 'primary winding, will actually offer a range -5%, -2.5%, 0, + 2.5%, + 5%.
• 4a and 4b is obtained by the tilting of two bipolar contactors 14 or, according to another possible variant (not shown), by the successive switching of four unipolar contactors.
• the technical solutions presented in FIGS. 2 and 3 use switching elements 10a, 10b, 10c, 10d, 12, 13, 14 which are unipolar or bipolar contactors, single phase or polyphase electromechanical type whose tilt is obtained using an electric actuator generally consisting of a solenoid.
• switching elements 10a, 10b, 10c, 10d, 12, 13, 14 which are unipolar or bipolar contactors, single phase or polyphase electromechanical type whose tilt is obtained using an electric actuator generally consisting of a solenoid.
• it is also possible to replace these electromechanical switching members by switching devices based on power semi-conductors such as thyristors. Nevertheless, the characteristics of these components as they can be currently supplied greatly limit their scope given the operating constraints.
• 10c, 10d, 12, 14 is contained in a truth table, an example of which is given in FIG. 4a which applies to the diagram of FIG. 4b.
• This truth table is stored in a control-command function carried out by a control interface 17 integrated in the adjustment device 3.
• the choice of the position results from information which may be of external origin to the device, coming from an information exchange device with a network manager, or possibly an internal one.
• different criteria can be used, for example the compound voltages U1 of the first voltage network 1 measured between the phases constituting the first electrical connection 6 situated between the control transformer 7 and the distribution transformer 5, or the composed voltages U2 measured between the phases of the second voltage network 2 associated with currents 12 discharged in the different phases of this same second voltage network 2.
• the main difficulty to overcome is to overcome the voltage transient occurring in the time interval between the opening of a switching member prior to the closed position and the closure of another organ previously opened. Indeed, two switching members can not be simultaneously closed without creating prejudicial short circuit situation for the distribution system. Furthermore, the brief time interval during which no switching member would be closed and during which the primary winding 8 would be open would result in a high impedance across the secondary winding 1 1 and therefore in a voltage transient no acceptable for the operation of the system.
• Figure 5 shows the solution that has been made to remedy this problem. It is represented here for a three-phase system, but can be considered for any type of polyphase system.
• a tertiary winding 13 On each phase of the control transformer 7, in addition to the primary windings 8 and secondary 1 1 is added a tertiary winding 13 said stabilization, positioned parallel to the other two windings and in the immediate vicinity of the secondary winding January 1.
• Each tertiary winding 13 of a phase is connected in series with the tertiary windings 13 of the other phases, to form for example a delta coupling if it is a three-phase system.
• Wait times of 50 ms approximately correspond to the mechanical switchover delay and the time of interruption or establishment of the electrical current. It follows a total switching time for a three-phase system of the order of 250 ms, fully compatible with the application of the adjustment device 3 relating to the public distribution of electrical energy. These delays can have a different value, depending on the speed of the contactors used.
• the advantage of the tertiary winding 13 stabilization is to replace the primary winding 8 during the period during which it is found in an open situation, that is to say during the waiting period between the opening of the N plug and the closing of the N + 1 plug, providing the necessary ampere-turns for compensation of the current flowing through the secondary winding 1 1.
• These ampere-turns are taken from the other phases on which no commutation is in progress.
• the secondary winding January 1 of the adjustment device 3 can be inserted between the distribution transformer 5 and the first voltage network 1 or between the distribution transformer 5 and the second voltage network 2.
• the choice may depend the power of the distribution transformer 5, and thus the transient intensities, but also the respective voltages of the networks 1 and 2. According to these characteristics and according to the technology adopted for producing the control transformer 7 included in the adjustment device 3, the one of the two options may be more economical.
• the adjustment transformer 7 of the adjustment device 3 is integrated directly into the envelope of the distribution transformer 5. This results in the saving of the second electrical connection 4 medium-voltage and connection interfaces associated with it. This gives a set whose size is less than that resulting from the combination of two separate devices.

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Supply And Distribution Of Alternating Current (AREA)
• Control Of Electrical Variables (AREA)

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• 2012
  • 2012-07-26 FR FR1257274A patent/FR2994039B1/fr not_active Expired - Fee Related
• 2013
  • 2013-07-26 EP EP13756607.1A patent/EP2878075A2/de not_active Withdrawn
  • 2013-07-26 WO PCT/FR2013/051810 patent/WO2014016532A2/fr not_active Ceased

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