Hybrid alternator with voltage regulator

A voltage regulator for controlling bidirectional current flow through a winding of an alternator to control an output voltage of the alternator, to the voltage regulator comprising:

• a voltage monitoring circuit connected to monitor an output voltage of the alternator, the voltage monitoring circuit producing an error signal indicating that the output voltage of the alternator should be increased or decreased;
• a switching circuit including a plurality of switches arranged in a bridge configuration connected to the winding to conduct current through the winding in a forward direction in forward polarity mode to increase the output voltage of the alternator and to conduct current in a reverse direction through the winding in a reverse polarity mode to decrease the output voltage of the alternator the switching circuit including:
• a first upper switch connected to a first end of the winding;
• a first lower switch connected to a second end of the winding, the first lower switch forming with the first upper switch a first pair of switches, the first pair of switches defining the forward polarity mode in which a forward polarity voltage is applied to the winding when the first pair of switches are closed;
• a second upper switch connected to the second end of the winding;
• and
• a second lower switch connected to the first end of the winding, the second lower switch forming with the second upper switch a second pair of switches, the second pair of switches defining the reverse polarity mode in which a reverse polarity voltage is applied to the winding when the second pair of switches are closed;
• a control circuit connected to the switching circuit to the switch alternator between the forward polarity and reverse polarity modes in response to the error signal;
• and
• a transient suppression circuit connected to the switching circuit to switch on an upper switch from one of the first and second pairs of switches and a lower switch from the other of the first and second pairs of switches to absorb a transient voltage spike in the output voltage of the alternator having a voltage in excess of a predetermined voltage.

A method of controlling bidirectional current flow through a winding of an alternator, the method comprising:

• switching a positive polarity voltage to the winding in a forward polarity mode to start or increase current flow in a forward direction through the winding;
• switching a reverse polarity voltage to the winding in a reverse polarity mode to start or increase current flow in a reverse direction through the winding;
• disconnecting the winding from the positive polarity voltage and the reverse polarity voltage in a decay mode to decrease the magnitude of current flow through the winding regardless of the direction of current flow in the winding;
• and
• connecting the winding to allow recirculating current flow through the winding during the decay mode as the magnitude of current flow through the winding is decreased.