Power convertor
AssigneeMitsubishi Electric Corporation
InventorsKoki Matsumoto, Sadayuki Inoue
Life of this patent
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Abstract
A virtual synchronous generator controller included in a controller of a power convertor generates a first command value of a frequency of a second voltage and a second command value of a phase of the second voltage by making an active power value and an active power target value correspond respectively to electrical energy and mechanical energy of a motion equation of a rotor of a synchronous generator to simulate an operation of the synchronous generator. When a turn-on condition is satisfied, a determination unit switches a connection state from a non-conduction state to a conduction state by controlling a relay that causes the connection state between an inverter and an AC power system to be selectively switched between the conduction state and the non-conduction state.
Claims6
A power convertor to convert a DC voltage from a DC power source into an AC voltage for an AC power system, the power convertor comprising:
- an inverter to convert the DC voltage into the AC voltage;
- a relay to cause a connection state between the inverter and the AC power system to be selectively switched between a conduction state and a non-conduction state;
- and
- a controller to receives a first measurement value of a first voltage between the relay and the AC power system, a second measurement value of a second voltage between the relay and the inverter, and a measurement value of a current flowing between the inverter and the AC power system, and to control the inverter and the relay,
- wherein
- the controller includes:
- a voltage controller to control an amplitude of the second voltage to cause the amplitude to become closer to a voltage amplitude target value;
- an active power calculator to calculate an active power value outputted to the AC power system, by using the first measurement value and the measurement value of the current;
- a virtual synchronous generator controller to generate a first command value of a frequency of the second voltage and a second command value of a phase of the second voltage by making the active power value and an active power target value correspond respectively to electrical energy and mechanical energy of a motion equation of a rotor of a synchronous generator to simulate an operation of the synchronous generator;
- a detector to detect a phase of the first voltage from the first measurement value;
- and
- a determination unit to control the relay to switch the connection state from the non-conduction state to the conduction state when a turn-on condition is satisfied;
- and
- the turn-on condition includes a first condition that an amplitude difference between an absolute value of the first measurement value and an absolute value of the second measurement value is included in a first tolerance, and a second condition that a phase difference between the phase of the first voltage and the second command value is included in a second tolerance.
Dependencies are inferred from the claim text.