Indirect calculation of bus voltage for voltage source inverter
AssigneeGeneral Electric Company
InventorPaul S. Bixel
Life of this patent
Estimating the term…
Abstract
A method and apparatus for determining accurate stored energy values and effective DC bus voltage values for a voltage source inverter. The technique includes the determination of an effective DC bus voltage for the VSI based on an output voltage and the modulation index of the VSI. Further, an estimated power flow can be integrated to obtain an estimated stored energy, which can then be used to determine the effective DC bus voltage of the VSI. The disclosed technique is accurate in both transient and steady-state conditions, and reduces the effects of long term error accumulation.
Claims35
A method for providing control to a voltage source inverter, comprising the steps of:
- a) measuring at least one output voltage of the voltage source inverter;
- b) determining a first effective DC bus voltage signal based on the at least one output voltage and a modulation index of the voltage source inverter;
- and
- c) providing control based on the determined first effective DC bus voltage signal.
A method for determining an effective DC voltage present within a voltage source inverter, comprising the steps of:
- determining at least a first output voltage of the voltage source inverter;
- determining at least a first output current of the voltage source inverter;
- estimating a power flow in the voltage source inverter based on the determined output voltage and current;
- integrating the estimated power flow;
- adding the integrated power flow to the estimated power flow to obtain an estimate of energy contained in the voltage source inverter;
- and
- dividing the estimate of stored energy by one-half of a nominal effective capacitance of the voltage source inverter and determining a square root of the divided stored energy to obtain an estimate of the effective DC bus voltage within the voltage source inverter.
An apparatus for providing control to a voltage source inverter, comprising:
- a plurality of connections to a corresponding plurality of outputs of the voltage source inverter;
- processing circuitry connected to receive at least a first output voltage from the plurality of connections, the processing circuitry determining a first effective DC bus voltage signal based on the at least a first output voltage and a modulation index of the voltage source inverter;
- and
- providing control based on the determined first effective DC bus voltage signal.
An apparatus for providing control to a voltage source inverter, comprising:
- a plurality of connections to a corresponding plurality of outputs of the voltage source inverter;
- and
- processing circuitry connected to receive at least one output voltage and at least one output current of the voltage source inverter, the processing circuitry estimating a power flow in the voltage source inverter from the at least one output voltage and current, integrating the estimated power flow to obtain an estimate of energy contained in the voltage source inverter, dividing the estimate of stored energy by one-half of a nominal effective capacitance of the voltage source inverter, determining a square root of the divided stored energy to obtain an estimate of the effective DC bus voltage within the voltage source inverter, and providing control to the voltage source inverter based on the estimated effective DC bus voltage.
A machine-readable storage medium for use in a general purpose processor, comprising:
- a) A machine-readable instruction for measuring at least one output voltage of a voltage source inverter;
- b) A machine-readable instruction for determining a first effective DC bus voltage signal based on the at least one output voltage and a modulation index of the voltage source inverter;
- and
- c) A machine-readable instruction for providing control based on the determined first effective DC bus voltage signal.
A machine-readable storage medium for use in a general-purpose processor, comprising:
- a machine readable instruction for determining at least a first output voltage of a voltage source inverter;
- a machine-readable instruction for determining at least a first output current of the voltage source inverter;
- a machine-readable instruction for estimating a power flow in the voltage source inverter based on the determined output voltage and current;
- a machine-readable instruction for integrating the estimated power flow;
- a machine-readable instruction for adding the integrated power flow to the estimated power flow to obtain an estimate of energy contained in the voltage source inverter;
- and
- a machine-readable instruction for dividing the estimate of stored energy by one-half of a nominal effective capacitance of the voltage source inverter and determining a square root of the divided stored energy to obtain an estimate of the effective DC bus voltage within the voltage source inverter.
Dependencies are inferred from the claim text.