A DC motor control device includes a communication circuit configured to receive a control command specifying a target rotation amount for a DC motor, a sensor interface configured to receive a detection signal from a rotational angle sensor that outputs the detection signal every time the DC motor rotates by a certain rotational angle, a step counter that outputs a count signal every time the detection signal has been received a certain number of times, a controller that, based on the number of times the count signal received, determines a step count representing the total amount of rotation, and generates a control signal that controls the DC motor in accordance with the step count and the target rotation amount, and a drive signal generation circuit that generates a drive signal that rotates the DC motor in accordance with the control signal.

The present subject matter is directed to a system and method for improving speed control of a pitch drive system of a wind turbine. In one embodiment, the pitch drive system includes a direct current (DC) motor having an armature and a series-field winding, a battery assembly having a positive terminal and a negative terminal, and a current-controlling device configured in series between the positive terminal of the battery assembly and the series-field winding. The battery assembly is configured to supply power to the pitch drive system and the current-controlling device is configured to supply current to the series-field winding so as to ensure a field flux does not equal zero. Thus, the current-controlling device has the effect of limiting the maximum speed of the DC motor.

The present subject matter is directed to a system and method for improving speed control of a pitch drive system of a wind turbine. In one embodiment, the pitch drive system includes a direct current (DC) motor having an armature and a series-field winding, a battery assembly having a positive terminal and a negative terminal, and a current-controlling device configured in series between the positive terminal of the battery assembly and the series-field winding. The battery assembly is configured to supply power to the pitch drive system and the current-controlling device is configured to supply current to the series-field winding so as to ensure a field flux does not equal zero. Thus, the current-controlling device has the effect of limiting the maximum speed of the DC motor.

An electric motor controller having a front face and a rear face, the front face carrying a plurality of AC output couplings and the controller carrying a converter configured to convert a received DC supply into an output AC supply for controlling an electric motor, the AC output couplings being disposed symmetrically about an axis of symmetry of the controller on the front face of the controller. Also described is an apparatus comprising: a DC series motor; and a first current supply configured to supply a first current to an armature of the DC series motor; a second current supply configured to supply a second current to a field winding of the DC series motor; and a controller configured to control the first current supply to supply the first current based on a required torque output for the motor, and to control the second current supply to supply the second current based on the first current.

An electric motor controller having a front face and a rear face, the front face carrying a plurality of AC output couplings and the controller carrying a converter configured to convert a received DC supply into an output AC supply for controlling an electric motor, the AC output couplings being disposed symmetrically about an axis of symmetry of the controller on the front face of the controller. Also described is an apparatus comprising: a DC series motor; and a first current supply configured to supply a first current to an armature of the DC series motor; a second current supply configured to supply a second current to a field winding of the DC series motor; and a controller configured to control the first current supply to supply the first current based on a required torque output for the motor, and to control the second current supply to supply the second current based on the first current.

An electric motor controller having a front face and a rear face, the front face carrying a plurality of AC output couplings and the controller carrying a converter configured to convert a received DC supply into an output AC supply for controlling an electric motor, the AC output couplings being disposed symmetrically about an axis of symmetry of the controller on the front face of the controller. Also described is an apparatus comprising: a DC series motor; and a first current supply configured to supply a first current to an armature of the DC series motor; a second current supply configured to supply a second current to a field winding of the DC series motor; and a controller configured to control the first current supply to supply the first current based on a required torque output for the motor, and to control the second current supply to supply the second current based on the first current.

A rotary electric machine includes a rotor that rotates around a rotation axis serving as a center and has a plurality of salient poles protruding in directions perpendicular to the rotation axis, and a stator that includes an annular structural body disposed radially outside the rotor and surrounding the rotor, and 6n windings provided along a circumferential direction of the structural body, a field signal for generating field magnetic flux and a drive signal for driving the rotor as a three-phase rotary electric machine being superimposed on each other to be input to each of the windings. n is a natural number equal to or larger than one.

A rotary electric machine includes a rotor that rotates around a rotation axis serving as a center and has a plurality of salient poles protruding in directions perpendicular to the rotation axis, and a stator that includes an annular structural body disposed radially outside the rotor and surrounding the rotor, and 6n windings provided along a circumferential direction of the structural body, a field signal for generating field magnetic flux and a drive signal for driving the rotor as a three-phase rotary electric machine being superimposed on each other to be input to each of the windings. n is a natural number equal to or larger than one.