Direct current power plant

Method of producing direct current (DC) power for an electric grid comprising:

• driving a permanent magnet synchronous motor generator (PMSMG) whereby the PMSMG generator outputs alternating current (AC) power;
• converting the AC power to DC power;
• wherein the PMSMG and the motor drive power board control said driving;
• providing the DC power to an electric grid;
• receiving an angle having a waveform;
• applying an increment to the angle;
• generating a sine/cosine pair for the angle;
• generating an inverter waveform based on the sine/cosine pair;
• and
• computing a phase error signal based on the sine and a cosine of the grid voltage;
• multiplying the sine by the voltage of the grid supply and defining a signal that contains AC and DC components wherein:
• the AC component has an amplitude variation based on amplitudes of the grid supply and the inverter waveform, and having a frequency equal to twice the frequency of the grid supply when loop is locked;
• the DC component has an amplitude variation based on a phase error between the grid supply and the inverter waveform;
• filtering the phase error thereby eliminating a part of the AC component not relevant to control and defining filtered phase error;
• and
• supplying the filtered phase error to the PI controller.