The invention discloses a method for MGP new energy grid-connected control, wherein, the synchronous motor is connected to a synchronous generator; the new energy module drives the synchronous motor to rotate through a frequency converter; the frequency converter controls the power transmission; and the synchronous motor drives the synchronous generator for grid connection. The present invention has the beneficial effects that: the control method and system provided by the invention can improve the stability and reliability of the grid.

The invention includes an inverter to convert a direct-current voltage from a direct-current power supply into an alternating-current voltage and apply the alternating-current voltage to a motor that rotationally drives a load, a direct-current-voltage detecting unit to detect a voltage in the direct-current power supply, a shunt resistance that is a current detecting unit to detect an electric current flowing to the inverter, and an inverter control unit to generate PWM signals for driving switching elements of the inverter on the basis of the voltage detected by the direct-current-voltage detecting unit and the electric current detected by the shunt resistance, to set a specific phase difference between a phase of a carrier signal used for generation of the PWM signals and a phase of the alternating-current voltage, and to control the inverter such that a frequency of the PWM signals are synchronized with a frequency of the alternating-current voltage, the frequency of the PWM signals being an integer multiple of three times the frequency of the alternating-current voltage.

The invention includes an inverter to convert a direct-current voltage from a direct-current power supply into an alternating-current voltage and apply the alternating-current voltage to a motor that rotationally drives a load, a direct-current-voltage detecting unit to detect a voltage in the direct-current power supply, a shunt resistance that is a current detecting unit to detect an electric current flowing to the inverter, and an inverter control unit to generate PWM signals for driving switching elements of the inverter on the basis of the voltage detected by the direct-current-voltage detecting unit and the electric current detected by the shunt resistance, to set a specific phase difference between a phase of a carrier signal used for generation of the PWM signals and a phase of the alternating-current voltage, and to control the inverter such that a frequency of the PWM signals are synchronized with a frequency of the alternating-current voltage, the frequency of the PWM signals being an integer multiple of three times the frequency of the alternating-current voltage.

A power regenerative converter, includes: a power module configured to include rectifiers and regenerative switches; a smoothing capacitor connected to direct-current power supply terminals, and that accumulates direct-current power during an alternating-current to direct-current conversion; a bus current detector that detects a bus current flowing between either of the direct-current power supply terminals and the smoothing capacitor; a power supply phase detector that detects a phase of an input power supply; a base drive signal generator that generates base drive signals that perform ON/OFF control of the regenerative switching elements based on a power supply phase detected by the power supply phase detection unit; a regeneration controller that performs a start and stop process of a power regenerative operation based on a detection result of the bus current detector and the base drive signals; and an overload detector that detects overload of a power regenerative converter based on the detection result of the bus current detector.

A power regenerative converter, includes: a power module configured to include rectifiers and regenerative switches; a smoothing capacitor connected to direct-current power supply terminals, and that accumulates direct-current power during an alternating-current to direct-current conversion; a bus current detector that detects a bus current flowing between either of the direct-current power supply terminals and the smoothing capacitor; a power supply phase detector that detects a phase of an input power supply; a base drive signal generator that generates base drive signals that perform ON/OFF control of the regenerative switching elements based on a power supply phase detected by the power supply phase detection unit; a regeneration controller that performs a start and stop process of a power regenerative operation based on a detection result of the bus current detector and the base drive signals; and an overload detector that detects overload of a power regenerative converter based on the detection result of the bus current detector.

Methods and systems for load alignment assistance are provided. An alignment current may be provided with a partial power converter through an n-phase supply line to a synchronous alternating current (AC) motor during a startup of a synchronous AC grid. The synchronous AC motor may receive polyphase AC power through the n-phase supply line from the synchronous AC grid during the startup. The partial power converter may be powered by a power source isolated from the synchronous AC grid. The alignment current may be controlled such that the alignment current causes a rotor of the synchronous AC motor to align with a rotor of a generator that powers the synchronous AC grid.

An air conditioner includes an inverter configured to drive a first motor for driving a first outdoor unit and a second motor for driving a second outdoor unit in parallel, and a processor. The processor is configured to determine parameters of the first motor and parameters of the second motor, compare the parameters of the first motor with the parameters of the second motor to determine whether the parameters differ by at least a certain value, and control the inverter through heterogeneous control for the first motor and the second motor based on the parameters differing by at least a certain value.

An air conditioner includes an inverter configured to drive a first motor for driving a first outdoor unit and a second motor for driving a second outdoor unit in parallel, and a processor. The processor is configured to determine parameters of the first motor and parameters of the second motor, compare the parameters of the first motor with the parameters of the second motor to determine whether the parameters differ by at least a certain value, and control the inverter through heterogeneous control for the first motor and the second motor based on the parameters differing by at least a certain value.