Electronic circuit for easier operation of multilevel converters
AssigneeDr. Ing. h.c. F. Porsche Aktiengesellschaft
InventorStefan Goetz
Life of this patent
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Abstract
Prior art electronic power supplies having distributed energy stores and/or the possibility to dynamically modify the connectivity of individual stores require complex monitoring of the input and output currents to and from the individual energy stores, often using a multitude of sensors, in order to allow for unrestricted operation. Examples of such power supplies include in particular modular multilevel converters and switched-capacitor circuits. The preen invention describes a possibility to determine the states of charge and energy levels of the energy stores using a small number of measuring systems.
Claims11
An electrical circuit comprising:
- at least two plurality of modules which each have at least one electrical energy store and at least one electronic switch configured to change electrical connections of the at least one electrical energy store to the energy stores of other modules of the plurality of modules, and
- at least one voltage-measuring device, coupled to the plurality of modules, configured to measure an electrical voltage generated by a group of two or more of the plurality of modules, in at least two different switched states s(t) of the modules within the group, and to automatically determine voltages of the electrical energy stores of the individual modules within the group from the electrical voltages generated by the group,
- wherein:
- the two or more modules each bring about at least two switched states which each define how the energy stores of the two or more modules are connected to one another in an electrically conductive fashion wherein one group of modules contains at least two or all of the modules of the electrical circuit, and
- the electrical circuit:
- (i) combines the automatically determined voltages of the electrical energy stores of the individual modules as coordinates in a vector V(t), and
- (ii) maps the automatically determined voltages as an electrical voltage Vunits(t) from the measured electrical voltage generated by the group at a respective time (t) as modeled by a matrix M(s(t)) that is a function of the at least two different switched states s(t), such that Vunit (s(t))=M(s(t)) dot product V(t).
A method for determining a respective voltage of a multiplicity of electrical energy stores, wherein in each case at least one electrical connection between individual energy stores is separated from one another by, in each case, at least one disconnecting electrical switching element, and wherein the multiplicity of electrical energy stores and disconnecting electrical switching elements are part of a modular electrical circuit, comprising at least the following steps which are carried out in a cyclically repeating fashion:
- measuring a respective electrical voltage formed by connection of the specified multiplicity of electrical energy stores in each of at least two different switched states s(t) of the specified disconnecting electrical switching elements;
- digitizing the specified measured electrical voltages;
- transmitting the digitized measured electrical voltages to at least one integrated electrical circuit;
- and
- estimating respective voltages of each of the multiplicity of electrical energy stores from the digitized measured electrical voltages for the specified multiplicity of electrical energy stores and the switched states which are associated with the specified disconnecting electrical switching elements utilizing the at least one integrated electrical circuit by:
- (i) combining the digitized measured electrical voltages for the specified multiplicity of electrical energy stores as coordinates in a vector V(t);
- and
- (ii) mapping the digitized measured electrical voltages as an electrical voltage Vunits(t) from the measured respective electrical voltage for the specified multiplicity of electrical energy stores at a respective time (t) as modeled by a matrix M(s(t)) that is a function of the at least two different switched states s(t), such that Vunit(s(t))=M(s(t)) dot product V(t).
Dependencies are inferred from the claim text.