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
  • H02M3/00—Conversion of dc power input into dc power output
  • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
  • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
• • 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
  • H02M1/00—Details of apparatus for conversion
  • H02M1/12—Arrangements for reducing harmonics from ac input or output
• • 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
  • H02M1/00—Details of apparatus for conversion
  • H02M1/42—Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
  • H02M1/4208—Arrangements for improving power factor of AC input
  • H02M1/4216—Arrangements for improving power factor of AC input operating from a three-phase input voltage
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
  • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
  • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
  • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
  • H02M7/06—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes without control electrode or semiconductor devices without control electrode
• • 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
  • H02M1/00—Details of apparatus for conversion
  • H02M1/0083—Converters characterised by their input or output configuration
  • H02M1/0085—Partially controlled bridges
• • 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
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
  • Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Definitions

• the present invention relates to a power converter type AC / DC arranged to improve the harmonic distortion rate (THDi) of the current taken from the power grid and the power factor.
• TDDi harmonic distortion rate
• a power converter has several input phases connected to the network, for example three input phases if it is connected to a three-phase network.
• a power converter includes a rectifier module for transforming the AC voltage supplied by the network into a DC voltage.
• the converter also comprises a DC supply bus having a first positive potential supply line and a second negative potential supply line to which the DC voltage is applied and a bus capacitor connected between the first power line and the second power line and intended to keep constant the DC voltage on the bus.
• an input current taken from the network is formed of peaks corresponding to the recharging the bus capacitor as soon as the input phase voltage becomes higher than the supply bus voltage.
• the rectifier module is single-phase or three-phase, the input current taken from the network is therefore far from sinusoidal because, in addition to its fundamental, it contains many harmonics.
• the harmonics of the input current are characterized by two known indicators called THDi ("Total Harmony Distortion of Current") and PWHD ("Partial Weighted Harmony Distortion").
• THDi corresponds to the current harmonic distortion rate which represents the rms value of the harmonics relative to the rms value of the fundamental current.
• PWHD introduces a weighting giving more weight to high frequency harmonics, especially those of the ranks 14 to 40.
• a known solution for reducing the THDi is to perform a filtering on the DC bus by adding a DC inductance, which, if its value is sufficiently large, ensures a continuous conduction, that is to say that the Rectifier current flowing on the bus, at the output of the rectifier, never drops to zero.
• the aim of the invention is to propose a power converter making it possible to obtain a reduced THDi ( ⁇ 5%) and a power factor approaching 1, in order to minimize the number of components used and to optimize the sizing. and the cost of the transformer present at the input.
• a power converter comprising:
• a continuous supply bus connected to the rectifier module and comprising a first supply line and a second supply line, a bus capacitor connected to the first supply line and the second supply line,
• a first controlled current source formed by a controlled electronic inductor designed to control the current flowing on the DC supply bus and,
• switching means connected on the one hand to the second controlled current source and to the third controlled current source and on the other hand to each of the input phases, said switching means being controlled to switch the current generated by the second controlled current source or the third current source controlled on one of the input phases,
• first control means arranged to control the first current source controlled so as to impose a current on the DC supply bus and second control means, synchronized with the first control means and arranged to control the second source of power; current and the third current source so as to impose a current on one of the selected input phases using the switching means.
• the controlled electronic inductance comprises an inductance and a variable voltage source.
• variable voltage source comprises an electronic converter comprising a first switching arm, a second switching arm and a capacitor connected in parallel, each switching arm comprising at least one electronic switch.
• the second controlled current source and the third controlled current source comprise an assembly formed of at least one switching arm connected between the first supply line and the second supply line and an inductor. connected to the midpoint of the switching arm and the switching means.
• the switching arm comprises for example two switches connected in series, the midpoint being located between the two switches.
• the switching means comprise a plurality of switches each connected to an input phase and for switching the current generated by the second controlled current source and the third controlled current source.
• the invention relates to a speed controller comprising an inverter stage provided with switching arms for converting a DC voltage into a variable voltage for supplying an electric load, this speed controller comprising a power converter as defined above connected. upstream of its inverter stage.
• FIG. 1 illustrates the operating principle of the power converter of the invention
• FIG. 2 schematically represents a preferred embodiment of the power converter according to the invention
• FIG. 3 schematically represents another embodiment of the power converter according to the invention
• FIG. 4 represents the control algorithm of the switching means employed in the power converter of the invention for routing the current on one of the input phases
• FIGS. 5A to 5D show curves representing the simple voltages of the input phases and the currents generated by each controlled current source.
• an AC / DC power converter comprises a rectifier module 1 and a DC supply bus connected to the rectifier module 1.
• the rectifier module 1 is connected to the network on two or three input phases a, b, c (three phases in FIG. 1).
• the rectifier module 1 is for example a diode bridge which makes it possible to straighten a AC voltage supplied by the network and apply a rectified voltage on the DC bus.
• the rectifier module 1 comprises several arms each composed of two diodes in series, each arm being connected to an input phase a, b, c by the midpoint located between the two diodes.
• the DC power supply bus is connected downstream of the rectifier module 1. It comprises a first positive potential V + supply line and a second negative potential V-supply line. At least one bus capacitor C bus is connected to each of the two power supply lines of the bus and makes it possible to maintain the bus voltage at a constant value.
• This power converter may for example be included in a variable speed drive comprising an inverter module (not shown) connected to its DC bus and provided with several controlled switching arms for chopping the DC voltage and obtaining a voltage variable intended to supply an electric charge.
• an inverter module (not shown) connected to its DC bus and provided with several controlled switching arms for chopping the DC voltage and obtaining a voltage variable intended to supply an electric charge.
• the power converter employs a first controlled current source Si1 for controlling the current flowing on the output DC bus supply of the rectifier module 1, this current I er p being hereinafter referred rectifier current .
• This first current source Si1 controlled may have different configurations and different locations in the power converter.
• the first current source Si1 is in the form of a controlled electronic inductance. It is then connected in series on the first supply line V + or the second supply line V- and comprises:
• the first current source Si1 controlled described above can be replaced by a converter well known "boost" type connected in series on the first power line V + or the second power line V- of the power converter.
• the first current source Si1 controlled can take the form of a triple "boost" rectifier. It then consists of the input inductors L in connected on the input phases a, b, c and of an active switching stage (T red ) realized on the rectifier module 1. The low or high diodes of the rectifier module are then replaced by bidirectional electronic switches, for example of the IGBT type.
• the first current source Si1 controlled takes the form of a controlled electronic inductance as shown in FIG. 2.
• this electronic inductor controlled is chosen to place this electronic inductor controlled on the first supply line V + of the bus.
• the reclp reclp current generated will then be positive.
• this electronic inductance is on the second supply line V-.
• the rectifier current (l red _ n not shown) generated will then be negative.
• the switching arms of the electronic converter 2 comprise for example each an electronic switch T1, T2 connected in series with a diode D1, D2.
• Each switching arm has a connection midpoint P1, P2 located between its electronic switch T1, T2 and its diode D1, D2.
• the connection midpoint P1 of the first switching arm is connected to the inductor L and the connection midpoint P2 of the second switching arm is connected to the bus capacitor C bus -
• the The series arrangement of the electronic switch and the diode is offset from that of the other switching arm.
• the electronic switches T1, T2 used in the electronic converter 2 are, for example, MOSFET type transistors controlled by suitable control means 3, for example using a PWM (Pulse Width Modulation) control. Other components capable of performing the same function can of course be used.
• the control of the two switches by PWM consists of comparing two signals in the form of saw teeth synchronized and in phase opposition with a constant control signal (commonly called modulating) in order to deduce the times and duration of switching of each of the switches of the electronic converter.
• the control of the switches electronic T1, ⁇ 2 provides a voltage value V across the terminals of the electronic converter 2 in the range [-V c , V c ].
• the electronic converter 2 thus behaves as a controlled variable voltage source for modulating the voltage V c across the capacitor C1 of the electronic converter 2 and thus to obtain the voltage V across the terminals of this electronic converter 2.
• V L1 V red - V bus - V aux (1)
• the power converter of the invention comprises two other current sources Si2, Si3 controlled identically, it is with the same input setpoint, by control means 30.
• the second current source Si2 and the third current source Si3 are connected in series between the first power supply line and the second supply line, upstream of the bus capacitor C bus and downstream with respect to the rectifier module 1.
• the power converter also comprises switching means connected on one side to the midpoint M1 located between the second current source Si2 and the third current source Si3 and each of the input phases a, b, c of the converter.
• these two current sources Si2, Si3 are for example formed by an assembly comprising at least one switching arm provided with at least two electronic switches QQ 2 and a common inductance L 2 connected to the point middle located between the two switches d, Q 2 .
• the switching means are connected to the inductance L 2 and to each of the input phases a, b, c of the converter. These switching means are used to direct the current generated by the second current source Si2 and the third current source Si3 to one of the three input phases a, b, c.
• the means of switching comprises three bi-directional switches S a , S b , S c connected in parallel, each of these switches S a , S b , S c connecting the inductance L 2 to a distinct input phase a, b, c.
• the two current sources Si2, Si3 are controlled identically by actuating the switches Q1, Q2. These two current sources Si2, Si3 are controlled to impose the current I on an input phase a, b, c selected by the switching means.
• the operating principle of the invention is to shape the rectifier current l red p with the aid of the first current source Si1 and to shape the current I t with the aid of the second current source Si2 and the third current source Si3 for sinusoidal input currents i a , i b , i c (THD i ⁇ 5%).
• control means 3, 30 of the three current sources Si 1, Si 2, Si 3 used are synchronized with each other so that the red p obtained by means of the first current source Si 1 corresponds to the maximum values of the currents input i a , i b i c and that the current I, obtained through the second and the third current source Si 2, Si 3, corresponds to the harmonic component of order 3 (at 150 Hz if the frequency of the grating is 50 Hz) of the input currents i a , i b , i c .
• the control means 3, 30 of the three current sources Si 1, Si 2, Si 3 used are synchronized with each other so that the red p obtained by means of the first current source Si 1 corresponds to the maximum values of the currents input i a , i b i c and that the current I, obtained through the second and the third current source Si 2, Si 3, corresponds to the harmonic component of order 3 (at 150 Hz if the frequency of the grating is 50 Hz) of the input currents
• U represents the effective voltage between phases of the electrical network and P out corresponds to the output power delivered at the output of the converter.
• Red _ I p (t) max (i (t), i B (t), i c (t))
• I t (t) - [max (i a (t), i b (t), i c (t)) + min (i a (t), i b (t), i c (t))]
• V corresponds to the peak voltage supplied by the network.
• the shaping of the currents I red p and I are synchronized with respect to the measured values of the single input voltages V a , V b , V c .
• T t f t ⁇ min (v a (t), V b (t), v c (t)) + max (v a (t), v b (t), v c (t)) ⁇
• l L is the charge current supplied to the electrical load connected downstream of the power converter.
• FIG. 4 shows the control algorithm of the switching means used to direct the current I t towards an input phase a, b, c of the network.
• this control algorithm one of the switches S a , S b , S c switching means is actuated according to the state of the single input voltages V a , V b , V c .
• the switch S a is actuated if: V a ⁇ V b and V a > V c or
• V a V c and V a > V b
• the switch S b is actuated if:
• V b V a and V b > V c or
• V b V c and V b > V a
• the switch S c is actuated if:
• V c V a and V c > V b or
• V c V b and V c > V a
• FIGS. 5A to 5D illustrate the operating principle of the invention.
• FIG. 5A shows the single input voltages V a , V b , V c .
• FIG. 5B shows the input current curves i a , i b , i c that one wishes to obtain.
• FIG. 5C shows the shape of the current I re d p imposed by the first current source Si1 and the shape of the current I, imposed by the second current source Si2 and the third current source Si3. It can be seen from this FIG.
• the current l re d p is formed by the control of the first current source Si1 so as to make it follow the maximum values of the currents i a , i b , i c and that the current I t is formed by the control of the second current source Si2 and the third current source Si3 so as to make it follow the order component 3 of the input currents i a , i b , i c .
• the minimum values of the input currents i a , i b , i c are obtained automatically as shown in FIG. 5D. (would correspond to l red _ n if the first current source Si1 was positioned on the second supply line V- of the DC bus).

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Rectifiers (AREA)
• Dc-Dc Converters (AREA)

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• 2010
  • 2010-12-20 FR FR1060845A patent/FR2969418B1/fr not_active Expired - Fee Related
• 2011
  • 2011-12-12 JP JP2013543681A patent/JP2013546299A/ja not_active Ceased
  • 2011-12-12 CN CN2011800614258A patent/CN103270679A/zh active Pending
  • 2011-12-12 US US13/996,299 patent/US9036370B2/en not_active Expired - Fee Related
  • 2011-12-12 EP EP11799399.8A patent/EP2656492A2/de not_active Withdrawn
  • 2011-12-12 WO PCT/EP2011/072445 patent/WO2012084572A2/fr active Application Filing

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