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
  • H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
  • H02M7/42—Conversion of DC power input into AC power output without possibility of reversal
  • H02M7/44—Conversion of DC power input into AC power output without possibility of reversal by static converters
  • H02M7/48—Conversion of DC power input into AC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
  • H02M7/483—Converters with outputs that each can have more than two voltages levels
  • H02M7/49—Combination of the output voltage waveforms of a plurality of converters

Definitions

• the invention relates to a method for dynamically adjusting a
• Wind turbines or solar systems as well as in vehicles such as hybrid or
• Electric vehicles increasingly electronic systems are used, which combine new energy storage technologies with electric drive technology.
• DC voltage in a multi-phase AC voltage for example, a three-phase AC voltage to be reversed.
• the DC link is fed by a string of serially connected battery modules.
• multiple battery modules are often connected in series in a traction battery.
• Energy storage module strings which are directly connectable to an electrical machine or an electrical network. This can be single-phase or multi-phase
• the energy storage module strands have a plurality of energy storage modules connected in series, each energy storage module having at least one battery cell and an associated controllable coupling unit, which allows the respective assigned at least one battery cell to be bridged as a function of control signals or the respectively assigned at least one battery cell to switch the respective energy storage module string.
• the coupling unit may be designed such that it additionally allows to switch the respectively associated at least one battery cell with inverse polarity in the respective energy storage module string or the respective
• Interrupt energy storage module string By suitable control of the
• Coupling units e.g. With the aid of pulse width modulation, suitable phase signals for controlling the phase output voltage can also be provided so that a separate pulse inverter can be dispensed with. The required for controlling the phase output voltage pulse inverter is thus integrated into the battery.
• BDIs usually have a higher level than conventional systems
• Harmonic content of their output voltage is ensured, inter alia, that defective, failed or not fully efficient battery cells can be bridged by appropriate control of their associated coupling units in the power supply lines.
• Phase output voltage of an energy storage module string can by
• Energy storage modules of an energy storage module string is determined.
• the present invention in one aspect, provides a method for dynamically adjusting short circuit conditions in an energy storage device that includes a plurality of power supply branches each having a plurality of
• Energy storage modules for generating a branch output voltage at a plurality of output terminals of the energy storage device comprises.
• Energy storage modules each have two module output terminals, one
• Coupling device having a first half-bridge of first coupling elements, which is coupled via a center tap to a first of the module output terminals, and a second half-bridge of second coupling elements, which is coupled via a center tap to a second of the module output terminals, and a
• Energy storage cell module with at least one energy storage cell, which is coupled between the first and second half-bridge on.
• the coupling device is adapted to the energy storage cell module in the respective
• the method comprises the steps of detecting a fault in one of the two half-bridges of one of the energy storage modules, detecting a current current direction of a
• the present invention according to another aspect provides an electrical
• energy supply branches each having a plurality of energy storage modules for generating a branch output voltage at a plurality of output terminals of the energy storage device.
• the energy storage modules each have two module output terminals, a coupling device with a first
• Half bridge of first coupling elements which via a center tap with a first the module output terminals is coupled
• a second half-bridge of second coupling elements which via a center tap with a second of the
• Module output terminals is coupled, and an energy storage cell module with at least one energy storage cell, which between the first and second
• the coupling device is designed to handle the
• the electric drive system further has a
• Control device which with the energy storage device for driving the
• Coupling means is coupled, and which is adapted to a
• the present invention provides an electrical
• a significant advantage of this approach is that the availability of the system, in particular an electric drive system, for example in an electrically powered vehicle, can be significantly improved. A time-limited emergency mode is therefore not necessary. The energy in the remaining, non-defective energy storage modules remains usable and can for
• Providing an output voltage of the energy storage device can be used.
• electrically powered vehicles is a Lying of the
• Coupling elements comprise IGBT power semiconductor switches or MOSFET power semiconductor switches, and detecting an error case may comprise detecting a failure of the controllability of the coupling elements.
• Power semiconductor switches can be advantageously used to optimize the efficiency and performance of the energy storage device.
• the detection of a failure of the controllability of the coupling elements may comprise measuring a voltage drop across the power semiconductor switches. Thereby, the presence of a malfunction in the power semiconductor switch can be detected reliably and efficiently.
• Bridging state setting a first bypass state via a first coupling element of the other of the two half-bridges for a first detected current direction and setting a second bridging state via a second coupling element of the other of the two half-bridges for a second detected
• Fig. 1 is a schematic representation of a system with a
• Fig. 2 is a schematic representation of an energy storage module of a
• Fig. 3 is a schematic representation of a method for dynamic
• Fig. 1 shows a schematic representation of a system 100 with a
• Energy storage device 1 for voltage conversion of provided in energy storage modules 3 DC voltage in an n-phase AC voltage.
• Energy storage device 1 comprises a plurality of power supply branches Z, of which three are shown by way of example in FIG.
• the energy supply branches Z can have a multiplicity of energy storage modules 3, which are connected in series in the energy supply branches Z.
• three energy storage modules 3 per energy supply branch Z are shown in FIG. 1, but each other number is shown
• Energy storage modules 3 may also be possible.
• the energy storage device 1 has at each of the power supply branches Z via an output terminal 1 a, 1 b and 1 c, which are respectively connected to phase lines 2a, 2b and 2c.
• the system 100 may further comprise a controller 6, which is connected to the energy storage device 1, and with the aid of which
• Energy storage device 1 can be controlled to the desired
• Output voltages to the respective output terminals 1a, 1 b, 1c provide.
• the energy storage modules 3 each have two output terminals 3a and 3b, via which an output voltage of the energy storage modules 3 can be provided. Since the energy storage modules 3 are primarily connected in series, the output voltages of the energy storage modules 3 add up to a total output voltage which can be provided at the respective one of the output terminals 1a, 1b and 1c of the energy storage device 1.
• the energy storage modules 3 each comprise one
• Coupling device 7 with a plurality of coupling elements 7a, 7c and 7b and 7d.
• Energy storage modules 3 furthermore each comprise an energy storage cell module 5 with one or more energy storage cells 5a to 5k connected in series.
• the energy storage cell module 5 can have, for example, serially connected batteries 5a to 5k, for example lithium-ion batteries or lithium-ion accumulators.
• the number of energy storage cells 5a to 5k in the energy storage module 3 shown in FIG. 2 is by way of example two, but any other number of energy storage cells 5a to 5k is likewise possible.
• the energy storage cell modules 5 are connected via connecting lines
• Coupling device 7 is formed in Fig. 2 as a full bridge circuit with two coupling elements 7a, 7c and two coupling elements 7b, 7d.
• the coupling elements 7a, 7b, 7c, 7d can each have an active switching element, for example a semiconductor switch, and a freewheeling diode connected in parallel thereto. It may be provided that the coupling elements 7a, 7b, 7c, 7d as MOSFET switches, which already have an intrinsic diode, or IGBT switches are formed.
• the coupling elements 7a and 7c can be used as left-side half-bridge 7e with center tap and the
• Coupling elements 7b and 7d may be formed as a right-side half bridge 7f with center tap.
• the center taps of the half bridges 7e and 7f are each connected to one of the module output terminals 3a and 3b.
• the coupling elements 7a, 7b, 7c, 7d can be controlled in such a way, for example with the aid of the control device 6 shown in FIG.
• Energy storage cell module 5 is selectively switched between the module output terminals 3a and 3b or that the energy storage cell module 5 is bridged. With reference to FIG. 2, the energy storage cell module 5, for example, in
• a first bridging state can be set, for example, by setting the two active switching elements of the coupling elements 7a and 7b in the closed state, while the two active switching elements of the
• Coupling elements 7c and 7d are kept in the open state. A second
• Switching elements of the coupling elements 7a and 7b are held in the open state, while the two active switching elements of the coupling elements 7c and 7d in
• the first bridging state can be referred to as the upper active short-circuit state, the second bridging state as the lower active short-circuit state, without limiting the generality.
• short-circuit state are selected from the point of view of the electric machine 2, since the respective machine windings are short-circuited In these states, the respective energy storage module 3 no longer has to provide an output voltage, that is, no current flows through the respective ones
• Energy storage modules 3 In the usual drive strategy, which can be performed for example by the controller 6 to drive the energy storage device 1, both short-circuit conditions can be integrated, either in alternating sequence or current direction-dependent.
• Coupling elements 7a and 7c or 7b and 7d one of the two half-bridges no longer controlled, in particular closing can be controlled. As a result, it is no longer possible to discharge the associated energy storage cells 5 a to 5 k, since they can no longer be switched in the required polarity into the energy supply branch Z.
• the problem may be that the freewheeling diodes of the coupling elements 7a to 7d inadvertently receive current when a short-circuit state is actually to be set, so that the energy storage cells 5a to 5k are charged inadvertently.
• the freewheeling diode of the coupling element 7c receives the current.
• a current flow path through the freewheeling diode of the coupling element 7c, the energy storage cell module 5 and the closed active switching element of the coupling element 7b is formed, resulting in a charging of the energy storage cells 5a to 5k.
• the entire energy supply branch Z with the defective energy storage module 3 can be shut down.
• this approach reduces the availability of the system 100 as a whole. It is therefore advantageous to have one
• Short circuit state in an energy storage module 3 with a defective half-bridge dynamically adjust to the energy storage module 3 safely in the
• the system 100 in FIG. 1 is used to supply a three-phase electric machine 2, for example in an electric drive system for an electrically operated vehicle.
• a three-phase electric machine 2 for example in an electric drive system for an electrically operated vehicle.
• Power supply network 2 is used.
• the power supply branches Z can at their connected to a neutral point end with a reference potential. 4
• the reference potential 4 may be, for example, a ground potential. Even without further connection with an outside of the
• FIG. 3 shows a schematic representation of a method 10 for dynamically setting short-circuit states in an energy storage device, in particular an energy storage device 1, as described in connection with FIGS. 1 and 2.
• the method 10 can be used, for example, for an energy storage device 1 of an electrically powered vehicle having an electric drive system 100 as shown in FIG. 1.
• a first step 11 first of all a detection of a fault in one of the half bridges 7e or 7f of one of the energy storage modules 3 of FIG
• An error case can be in particular an unwanted operating state, in which the functionality of the active
• Coupling element done.
• An intact, switched-on power semiconductor switch should have a small voltage drop compared to the output voltage of the energy storage cell module 5.
• a detection of an instantaneous current direction of a current flow through the energy supply branch Z of the energy storage module 3 affected by the fault can take place.
• a driving of the coupling elements 7a, 7c; 7b, 7d of the other of the two half-bridges 7e and 7f for setting a bridging state of the affected with the fault energy storage module 3 in dependence on the detected instantaneous current direction is preferably done in dynamic
• Change that is, it may be a setting of a first lock-up state via a first coupling element 7a, 7b, 7c, 7d of the other of the two half-bridges 7e and 7f for a first detected current direction and setting a second
• Bridging state via a second coupling element 7a, 7b, 7c, 7d of the other of the two half-bridges 7e and 7f take place for a second detected current direction.
• the coupling element 7b of the right-side half-bridge 7f may be closed to establish a safe active upper short circuit condition.
• the coupling element 7d of the right half bridge 7f closed to establish a safe active lower state short circuit.
• Power supply branch Z is provided, so can be changed in the change of the half-waves of the branch current in the power supply branch Z between the first and second bypass state back and forth.
• Energy storage device 1 increases uncontrollably without any of the
• Energy storage cell module 5 of the affected with the defect energy storage module 3 is almost fully charged, because then only a small amount of residual energy safely in the
• Energy storage cell module 5 can be safely deposited, and the
• the method 10 is therefore suitable for safely and permanently bridging a defective energy storage module 3 in a power supply branch Z without

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Charge And Discharge Circuits For Batteries Or The Like (AREA)

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Citations (5)

• 2012
  • 2012-06-04 DE DE102012209392A patent/DE102012209392A1/de not_active Withdrawn
• 2013
  • 2013-05-03 WO PCT/EP2013/059206 patent/WO2013182357A1/fr not_active Ceased

Patent Citations (5)

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