Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F27/00—Details of transformers or inductances, in general
  • H01F27/28—Coils; Windings; Conductive connections
  • H01F27/2804—Printed windings
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F29/00—Variable transformers or inductances not covered by group H01F21/00
  • H01F29/14—Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias
  • H01F2029/143—Variable transformers or inductances not covered by group H01F21/00 with variable magnetic bias with control winding for generating magnetic bias
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
  • H01L2924/19—Details of hybrid assemblies other than the semiconductor or other solid state devices to be connected
  • H01L2924/1901—Structure
  • H01L2924/19011—Structure including integrated passive components

Definitions

• the present invention relates to power circuit control systems requiring galvanic isolation between the control and the power circuit. These are generally load control systems powered by the AC grid. The main role of galvanic isolation is to protect the control circuit and its user.
• FIG. 1 very schematically represents a first conventional example of a galvanic isolation device between a control circuit and a power circuit. It is a transformer T forming an isolation barrier IB and a primary winding Tl of which is connected to two output terminals of a control circuit 1 and a secondary winding T2 of which controls a power switch K.
• the switch K consists of a thyristor connected between two terminals 2 and 3 of the power circuit not shown.
• the trigger (cathode) of the thyristor K is connected to a first terminal of the winding T2, the other terminal of which is connected to the terminal 3 generally representing a reference potential (for example, ground).
• control circuit 1 On the primary side, the control circuit 1 is generally supplied by a low voltage source (not shown). There are either transformers low frequency control (up to a few tens of ilohertz), ie transformers excited by a synchronous pulse at each alternation of an AC supply voltage on the secondary side.
• transformers low frequency control up to a few tens of ilohertz
• transformers excited by a synchronous pulse at each alternation of an AC supply voltage on the secondary side A disadvantage of control systems of the type illustrated in FIG. 1 is that it requires a discrete transformer, therefore bulky and expensive.
• FIG. 2 represents a second known example of a galvanically isolated control system.
• the crossing of the isolation barrier IB is optical.
• CTRL circuit 4
• PWCTRL circuit 5
• the switch K is connected between two terminals 2 and 3 downstream of the isolation barrier.
• it is also a thyristor, the trigger of which is connected to the control circuit 5.
• control electronics circuit 5 downstream of the isolation barrier is most often a major drawback.
• galvanic isolation barriers are known.
• the simplest consists of capacitors placed on each conductor to be insulated.
• the capacitors must then withstand high voltages and are therefore bulky and expensive.
• they require control electronics to control the thyristor or the triac constituting the switch downstream of the isolation barrier.
• the present invention aims to propose a control system for a power switch which respects the constraints of a galvanic isolation between a control part and a power part and which does not require control electronics downstream of this barrier. isolation.
• the invention also aims to propose a space-saving and inexpensive solution.
• the present invention provides a circuit for controlling a power switch by means of at least one galvanic isolation transformer produced in the form of flat conductive windings on an insulating substrate on which components are integrated. passive components of an oscillating high frequency excitation circuit of a primary winding of the transformer, the substrate of the transformer being attached to a wafer on which is mounted a circuit chip integrating the power switch.
• an active component of the oscillating circuit for controlling the transformer is produced in the form of an integrated circuit chip attached to a face of said substrate opposite to the wafer on which this substrate is mounted.
• the excitation frequency of the transformer by the oscillating circuit is greater than 40 MHz.
• said substrate is made of glass.
• a secondary winding of the transformer is connected to an electrode for controlling the power switch by means of a diode, the latter acting, with a parasitic capacitance of the electrode. control of the power switch, the role of a peak detector.
• the power switch is a thyristor or a triac.
• the circuit comprises two transformers for controlling two power switches respectively associated with a polarity of an alternating supply, the two primary windings of the two transformers being controlled by the same oscillating circuit.
• the invention also provides a device for transmitting and receiving a high frequency signal on a low frequency power supply network, comprising: a transmitter made up of an oscillating high frequency excitation circuit of a primary winding a first transformer, a secondary winding of which is connected to the network conductors; and a receiver consisting of a second galvanic isolation transformer for controlling a switch, at least said first transformer being produced in the form of flat conductive windings on a first insulating substrate on which are integrated passive components constituting the circuit oscillating.
• said second transformer is produced in the form of flat conductive windings on a second insulating substrate, the second substrate being attached to a wafer on which is mounted a circuit chip integrating the switch.
• FIGS. 1 and 2 which have been exposed previously are intended to expose the state of the art and the problem posed;
• Figure 3 shows, very schematically and simplified, an embodiment of a control circuit of a power switch according to the present invention;
• FIG. 4 represents a top view of an embodiment of a circuit integrating an isolation transformer according to the present invention;
• FIG. 5 represents an embodiment of a very high frequency control circuit and of an isolation transformer according to the present invention;
• Figure 6 is a schematic sectional view of an integrated circuit according to the present invention;
• FIG. 7 shows an embodiment of a control circuit for two power switches according to the present invention;
• FIG. 8 represents an example of application of the circuit of the invention for conveying control signals in a power switch through an alternating power supply network.
• FIG. 3 represents an embodiment of a circuit 10 for controlling a power switch K with galvanic isolation (barrier IB).
• the representation of Figure 3 is to be compared to those of Figures 1 and 2 conventional.
• a very high frequency transformer 11 (several tens of MHz at least) is used, a primary winding 12 of which is controlled by a circuit 13 (OSC).
• OSC circuit 13
• a secondary winding 14 of the transformer 11 is used to control a power switch K downstream of the isolation barrier IB.
• the switch K is connected between two terminals 2 and 3 of the circuit to be controlled.
• the switch K consists of a thyristor
• the trigger (of cathode) is, according to the invention, connected to a first terminal of the winding 14 by a diode Dl, the cathode of the diode Dl being connected to the trigger of thyristor K.
• the role of the diode Dl is to constitute, with the junction capacity of the thyristor K, a peak signal detector in the winding 14.
• circuit 13 constitutes an oscillator powered by a low direct voltage (VCC-GND).
• a control terminal 15 receives an invalidation signal from the oscillator of circuit 13.
• a output terminal 16 of circuit 13 is connected to a first terminal of the primary winding 12 of the transformer 11, the second terminal of the winding 12 being connected to ground GD.
• a feature of the present invention is to use a transformer 11 integrated on an insulating substrate (preferably glass).
• the excitation frequency thereof is, according to the invention, several tens of MHz and, preferably, greater than 40 MHz.
• Another characteristic of the present invention is to take advantage of the insulating substrate of the transformer to integrate therein all the passive components constituting the control circuit 13.
• Another characteristic of the invention is to use the insulating substrate on which the transformer 11 is integrated to isolate the passive components integrated on this substrate, with respect to the power electrodes of the switch on the secondary side. This characteristic of the invention will emerge more clearly from the subsequent description of FIG. 6.
• Figures 4 and 5 show, respectively by the equivalent electrical diagram and a top view of the insulating substrate, an embodiment of the oscillating circuit 13, the control circuit 10 and the transformer 11 of the invention.
• the circuit 13 consists of an oscillator of the collpits type. It comprises a bipolar transistor of NPN N type. The collector of transistor N is connected to a terminal 23 for applying the supply voltage VCC. Its transmitter is connected, by a capacitor C1, to a first end 12 ′ of the primary winding 12 of the transformer 11. The base of the transistor N is connected, by an inductance L in series with a capacitor C2, to the terminal 22 of GND mass.
• the base of transistor N is also connected to midpoint 24 of a series association of two resistors RI and R2 constituting a polarization divider bridge between terminals 23 and 22.
• Two capacitors C3 and C4 in series connect the base of transistor N to ground.
• the midpoint 25 of this series association is connected to the emitter of transistor N.
• This is a perfectly conventional diagram of a negative resistance oscillator obtained by the feedback on the emitter of the transistor (junction base-emitter and capacitors C3 and C4).
• a resistor R3 connects the emitter of transistor N to a control input 26. Resistor R3 polarizes the transistor and fixes the collector (or emitter) current.
• the base-emitter voltage of transistor N is fixed by the ratio of the resistance RI to the sum of the resistors R2 and R3.
• the oscillator is active.
• terminal 26 is connected to the positive potential VCC, which cancels the collector-emitter voltage of transistor N.
• the oscillation frequency is given by the relation l / (2 ⁇ VLC), where C represents the equivalent capacity of the capacitors C2, C3 and C4 in series, neglecting the parasitic capacities of the transistor.
• the substrate (shown schematically by a dotted line in FIG. 4) is a glass substrate on which are deposited conductive layers of realization of the integrated passive components.
• a first metallization level is deposited on the glass substrate and is used to define tracks 33 and 38 for connecting the central ends of planar windings 12 and 14 constituting the transformer 11.
• a second metallization level 31 defines a ground plane intended to be connected (terminal 22, figure 4) outside the circuit.
• three metallization levels are used which are separated from each other by an insulator.
• the metallization levels and in particular the second (ground plane) include openings participating in the production of the components.
• the transformer 11 is produced by means of two flat and concentric conductive tracks. These tracks are respectively produced, for example, in the second and third metallization levels.
• a first track defines the primary winding 12, a first end 12 'of which is connected, by the section 33 in the first metallization level, to the ground plane 31.
• a second end 12 "of the winding 12 is connected to a first electrode of the capacitor C1 made, for example, in the second level
• a second electrode of the capacitor C1, produced for example in the first level is connected to a conductive section 25 ′ of the second level representing the midpoint 25 of FIG.
• the section 25 connects an emitter terminal 27 of the transistor N to a first electrode of the capacitor C3 made for example in the first level, to a first electrode of the capacitor C4 made for example in the second level, to the second electrode of the capacitor Cl and to a first terminal of the resistor R3.
• the resistor R3 is, like the resistors RI and
• a second electrode of capacitor C4 formed for example in the first level, is connected to the ground plane 31.
• a second electrode of the capacitor C3, formed for example in the second level is connected to a conductive section 24 ′ of the second level symbolizing point 24 of FIG. 4.
• the section 24 ' connects a base terminal 28 of the transistor N, the second electrode of the capacitor C3, a first electrode of the capacitor C2, formed for example in the second level and respective first terminals of the resistors RI and R2.
• the second terminal of the resistor RI is connected to a terminal 29 representing the collector of the transistor N.
• the second terminal of the resistor R2 is connected to the ground plane 31.
• the second electrode of the capacitor C2 formed for example in the first level, is connected to a first end of a plane concentric winding, produced in the second level in an opening 34 of the ground plane and defining the inductance L.
• the second (central) end of the winding of the inductance L is connected , by a section 35 of the third level passing over the winding, to the ground plane 31.
• the secondary winding of the transformer 11 is obtained by means of a conductive trace 14 of the third level, concentric with the winding 12, and whose the two ends are connected to studs 36 and 37 of the circuit.
• the central end of the winding 14 is connected by the section 38 of the first level, to a track connecting the terminal 37.
• the various connections between the conductive levels are carried out by means of vias.
• the primary and secondary windings of the transformer 11 have the same number of turns.
• the transformation ratio is therefore 1.
• the second level of metallization in which the ground plane is produced is the level in which most of the connecting tracks are also produced.
• Other configurations are of course possible.
• the transformer 11 is then produced by means of two concentric and coplanar conductive tracks. These tracks are produced in the first metallization level forming the ground plane in openings of which are also produced, as in FIG. 5, connection tracks, electrodes of the capacitors, the winding L and the resistors.
• the secondary winding of the transformer 11 is obtained by means of a layout, nested concentric and coplanar with the primary winding. The connections of the central ends of the windings with peripheral elements are made in the second level.
• the dielectric of the transformer 11 consists of air
• FIG. 6 represents, by a very schematic view, a circuit according to the invention seen in section and integrated with the switch K.
• a silicon chip 40 in which the circuit breaker is made power K is reported on a substrate 42, for example, a printed circuit board or case.
• Different conductive tracks may be present on the substrate and have been symbolized by a metallization layer 41.
• the thyristor 40 is shown in FIG. 6 very schematically and is symbolized by a substrate 43 of type N, one rear face of which
• the wafer or glass substrate 20 carrying the passive components integrated is also attached to the substrate 42 by its rear face (opposite to that provided with metallizations in which the various components are made).
• the various passive components On the front face of the glass substrate 20, the various passive components have been symbolized by a layer 47 from which the three conductors 22, 23 and 26 of the control circuit leave and, in the direction of the chip 40, a conductor 48 connecting the pad 36 (FIG. 5) at the cathode 3 of the switch K, and a conductor 49 connecting the other pad '37 of the secondary winding 14 of the transformer 11 to the region 44.
• FIG. 6 represents a variant of the invention in which the transistor N (FIG. 4) is attached in the form of an integrated circuit chip 50 on the front face of the glass substrate 20.
• the adaptation of this front face for revealing the contact pads of the collector, the emitter and the base of the transistor N opposite those of the chip 50 is within the reach of those skilled in the art.
• the glass substrate 20 not only plays the role of galvanic isolation barrier of the transformer 11 but also serves to electrically isolate the control circuit from the tracks of the printed circuit 42. This is particularly interesting since, more often than not, components other than the thyristor K and the diode D1 are added to the substrate 42.
• the passive components of the circuit of the invention on a glass substrate having a size of the order of 5 to 10 millimeters per side.
• the value of the inductance L is preferably less than one hundred nanohenry.
• the value of the different capacitors is, from preferably less than nanofarad.
• the values of the different resistances are preferably less than 100 kiloohms.
• An advantage of the present invention is that it makes it possible to integrate all the constituents of a control circuit of a power switch, without however requiring low voltage control circuits downstream of the isolation barrier with respect to to the control signals.
• Another advantage of the invention is that at the frequencies chosen for the transformer, the capacitors of the oscillator of its control circuit remain integrable.
• An advantage of the present invention is that the control circuit is considerably less bulky than conventional systems.
• Another advantage of the invention is that it is no longer necessary to position an optical transmitter relative to a receiver, which, even in an integrated manner, is difficult to obtain. in classic circuits.
• FIG. 7 represents a second embodiment of a power switch control circuit according to the invention.
• two thyristors Thl and Th2 are used downstream of the isolation barrier IB.
• the anode of thyristor Thl and the cathode of thyristor Th2 are connected to terminal 2.
• the cathode of thyristor Thl and the anode of thyristor Th2 are connected to terminal 3.
• the respective triggers of thyristors Thl and Th2 are connected to cathodes diodes D1 and D2, the respective anodes of which are connected to first ends 51 and 52 of secondary windings 53 and 54 of separate isolation transformers 55 and 56.
• Each isolation transformer 55 and 56 is produced in accordance with which has been explained above in relation to the first embodiment. Consequently, respective primary windings 57 and 58 of transformers 55 and 56 are controlled by an oscillating circuit 13.
• a single oscillating circuit 13 is sufficient, its output 16 being connected to a first end of each winding 57 and 58, the second ends of which respective are connected to ground 22 on the primary side.
• the ends of the windings 53 and 54 are connected, respectively, to the terminals 2 and 3.
• the operation of the circuit of FIG. 7 is deduced from that exposed above in relation to FIG. 4.
• FIG. 8 represents the simplified electrical diagram of an application of the present invention to the transmission of control signals through the electrical supply network (the sector).
• This network is symbolized in FIG. 8 by two conductors P and N carrying a low frequency alternating voltage (for example, 220 volts, 50 Hz).
• a transmitter 60 is provided at a point in the network.
• This transmitter uses a first transformer 61 according to the invention controlled by a wired circuit 13 as in the previous embodiments.
• the modulation of the signal to be transmitted is, for example, carried out by the invalidation command (terminal 26) of circuit 13.
• the primary 62 of the transformer 61 is upstream of a first isolation barrier IB1 which isolates the control of the transformer of the electrical network.
• the secondary winding 64 of the transformer is connected by each of its ends to the conductors P and N of the sector.
• a connection capacitor Ca is inserted between one of the mains conductors and the winding 64.
• a receiver 70 is provided for very high frequency signals sent by the transformer 61.
• a transformer 71 is used to convey these signals through a second isolation barrier IB2 of the reception circuit with respect to the electrical network.
• a primary winding 72 of the transformer 71 is connected to the conductors P and N of the sector.
• a capacitor Decoupling Cb is preferably inserted between one of the conductors and one end of the winding 72.
• a secondary winding 74 of the transformer 71 is connected to the control side of a power switch K.
• the two electrodes power 2 and 3 of switch K are connected in series with a load or with a load to be controlled.
• a diode D1 is interposed between the control electrode (for example, the trigger of a thyristor) and the winding 74.
• the transformer 71 is a very high frequency transformer according to the invention .
• the oscillator 13 and the transformer 61 are integrated on the same glass substrate.
• the transformer 71 is integrated on a glass substrate.
• the switch K and the diode Dl are produced in the form of an integrated circuit chip attached to the same insulating substrate as the transformer 71.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Semiconductor Integrated Circuits (AREA)
• Inductance-Capacitance Distribution Constants And Capacitance-Resistance Oscillators (AREA)
• Inverter Devices (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8858052

Family Applications (1)

Country Status (5)

Families Citing this family (23)

Family Cites Families (13)

• 2000
  • 2000-12-21 FR FR0016837A patent/FR2818824B1/fr not_active Expired - Fee Related
• 2001
  • 2001-12-20 EP EP01990605A patent/EP1350258A2/de not_active Withdrawn
  • 2001-12-20 US US10/182,420 patent/US6862196B2/en not_active Expired - Lifetime
  • 2001-12-20 CN CNB018210767A patent/CN1227802C/zh not_active Expired - Fee Related
  • 2001-12-20 WO PCT/FR2001/004136 patent/WO2002050850A2/fr not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events