Mid-voltage variable-frequency driving system and total harmonic distortion compensation control method
AssigneeDelta Electronics (Shanghai) Co., Ltd.
InventorsWei CHEN, Bo-Yu PU, Yi ZHANG
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Abstract
A mid-voltage variable-frequency driving system and a total harmonic distortion compensation control method are provided in this invention. The mid-voltage variable-frequency driving system includes a total harmonic distortion compensation unit. The total harmonic distortion compensation unit is used to perform an optimal adjustment on a reactive component reference value of a grid-side phase current, such that a harmonic component of the grid-side phase current may be reduced and a power factor of a three-phase switch-mode rectifier module within the mid-voltage variable-frequency driving system may be maintained.
Claims38
A total harmonic distortion compensation control method, used in a three-phase switch-mode rectifier module, wherein the three-phase switch-mode rectifier module is coupled to a three-phase electrical grid for converting an AC voltage input on the three-phase electrical grid into a DC voltage, and the total harmonic distortion compensation control method comprises:
- performing harmonic detection on a grid-side phase current flowing into the three-phase switch-mode rectifier module;
- stopping adjusting a reactive component reference value of the grid-side phase current when a harmonic component of the grid-side phase current does not reach a predetermined harmonic value, so as to form a final reactive component reference value, or further determining a phase angle difference between a fundamental component of a rectifier AC-side phase current and a fundamental component of a rectifier AC-side phase voltage of the three-phase switch-mode rectifier module when a harmonic component of the grid-side phase current exceeds the predetermined harmonic value;
- Stopping adjusting the reactive component reference value when the phase angle difference is a predetermined phase angle difference value, or further determining a power factor of the three-phase switch-mode rectifier module when the phase angle difference is not a predetermined phase angle difference value;
- and
- Stopping adjusting the reactive component reference value when the power factor does not reach a predetermined power factor value, or adjusting the reactive component reference value when the power factor exceeds the predetermined power factor value, so as to change the final reactive component reference value.
A total harmonic distortion compensation control method for a mid-voltage variable-frequency driving system comprising a three-phase switch-mode rectifier module, a three-phase electrical grid, a controller and a total harmonic distortion compensation unit, wherein the three-phase switch-mode rectifier module is coupled to the three-phase electrical grid, and the controller is coupled to the three-phase switch-mode rectifier module, and the total harmonic distortion compensation unit is coupled to the controller, and the total harmonic distortion compensation control method comprises:
- inputting an initial reactive component reference value into the total harmonic distortion compensation unit, wherein the total harmonic distortion compensation unit adjusts the initial reactive component reference value to generate a final reactive component reference value;
- and
- controlling each single-phase rectifier circuit of the three-phase switch-mode rectifier module through the controller according to the final reactive component reference value generated by the total harmonic distortion compensation unit, thus adjusting a phase angle difference of the three-phase switch-mode rectifier module, thereby adjusting a power factor corresponding to the three-phase electrical grid and eliminating a current total harmonic distortion corresponding to the three-phase electrical grid, wherein the phase angle difference exists between a fundamental component of a rectifier AC-side phase current and a fundamental component of a rectifier AC-side phase voltage of each single-phase rectifier circuit of the three-phase switch-mode rectifier module.
A mid-voltage variable-frequency driving system coupled to a three-phase electrical grid for driving an induction motor, the mid-voltage variable-frequency driving system comprising:
- a three-phase switch-mode rectifier module coupled to the three-phase electrical grid for converting an AC voltage input on the three-phase electrical grid into a DC voltage;
- a controller coupled to the three-phase switch-mode rectifier module, wherein the controller compares a sampled reactive component of a grid-side phase current from the three-phase electrical grid with a final reactive component reference value, thereby obtaining a first comparison result, and thus controls the three-phase switch-mode rectifier module according to the first comparison result until the reactive component approaches the final reactive component reference value;
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- a total harmonic distortion compensation unit, wherein the total harmonic distortion compensation unit is used for performing an optimal adjustment on the reactive component reference value such that a harmonic component of the grid-side phase current is reduced while the power factor is maintained.
A total harmonic distortion compensation control method for a mid-voltage variable-frequency driving system comprising a three-phase switch-mode rectifier module, a three-phase electrical grid, a controller and a total harmonic distortion compensation unit, wherein the three-phase switch-mode rectifier module is coupled to the three-phase electrical grid, and the controller is coupled to the three-phase switch-mode rectifier module, and the total harmonic distortion compensation unit is coupled to the controller, and the total harmonic distortion compensation control method comprises:
- inputting a initial reactive component reference value into the total harmonic distortion compensation unit, wherein the total harmonic distortion compensation unit adjusts the initial reactive component reference value to generate a reactive component reference value;
- and
- controlling each single-phase rectifier circuit of the three-phase switch-mode rectifier module through the controller according to the final reactive component reference value generated by the total harmonic distortion compensation unit, thus adjusting a phase angle difference of the three-phase switch-mode rectifier module, thereby adjusting a power factor corresponding to the three-phase electrical grid and eliminating a current total harmonic distortion corresponding to the three-phase electrical grid, wherein the phase angle difference exists between any two voltage or current components from the rectifier AC-side to the three-phase electrical grid side.
Dependencies are inferred from the claim text.