Control device and power conversion system
AssigneeToshiba Mitsubishi-Electric Industrial Systems Corporation
InventorsTomoya KATSUKURA, Yoshihiro TAWADA, Issei FUKASAWA, Masahiro KINOSHITA
Life of this patent
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Abstract
A control device includes a modulation rate calculator configured to calculate a modulation rate based on a DC voltage on a DC side an, a limiter configured to update a DC voltage command lower bound limiter based on the lower bound limiter operation value; a maximum power point tracking controller configured to calculate a first DC voltage command value and determine a second DC voltage command value based on the calculated first DC voltage command value and the DC voltage command lower bound limiter set to the limiter, and an inverter controller configured to control an inverter of the power conversion system based on the second DC voltage command value.
Claims9
A control device in a photovoltaics power conversion system connected to a solar panel on a DC side, the control device comprising:
- a modulation rate calculator configured to calculate a modulation rate based on a DC voltage on a DC side of the power conversion system and a grid voltage root mean square value on an AC side of the power conversion system;
- a limiter adjuster configured to calculate a lower bound limiter operation value based on a predetermined lower bound limiter set value, the grid voltage root mean square value, and a predetermined rated value in accordance with the modulation rate calculated by the modulation rate calculator;
- a limiter configured to update a DC voltage command lower bound limiter based on the lower bound limiter operation value calculated by the limiter adjuster;
- a maximum power point tracking controller configured to calculate a first DC voltage command value by performing maximum power point tracking control based on DC power generated by the solar panel and determine a second DC voltage command value based on the calculated first DC voltage command value and the DC voltage command lower bound limiter set to the limiter;
- and
- an inverter controller configured to control an inverter of the power conversion system based on the second DC voltage command value determined by the maximum power point tracking controller.
A control device in an energy-storage-system power conversion system connected to an energy storage system on a DC side, the control device comprising:
- a modulation rate calculator configured to calculate a modulation rate based on a DC voltage on a DC side of the power conversion system and a grid voltage root mean square value on an AC side of the power conversion system;
- a limiter adjuster configured to calculate an operation range lower bound voltage operation value based on a predetermined operation range lower bound voltage set value, the grid voltage root mean square value, and a predetermined rated value in accordance with the modulation rate calculated by the modulation rate calculator;
- a limiter configured to update the operation range lower bound voltage based on the operation range lower bound voltage operation value calculated by the limiter adjuster;
- a DC voltage operation range detector configured to compare the DC voltage on the DC side of the power conversion system and the operation range lower bound voltage set to the limiter and determine whether the DC voltage is smaller than the operation range lower bound voltage;
- and
- an operation controller configured to stop an inverter of the power conversion system when it is determined by the DC voltage operation range detector that the DC voltage is smaller than the operation range lower bound voltage.
Dependencies are inferred from the claim text.