Reversible DC motor drive including a DC/DC converter and four quadrant DC/DC controller

A reversible direct current (DC) motor drive for a DC motor having a speed, said DC motor including first and second terminals for an armature winding having an armature voltage and an armature current, said DC motor also including third and fourth terminals for a field winding having a field voltage and a field current, said DC motor drive comprising:

• a DC/DC converter having a DC input and at least three output terminals, said output terminals including a first output terminal having a first pulsed DC voltage with a first DC voltage value, a second output terminal having a second pulsed DC voltage with a second DC voltage value, and a third output terminal having a third pulsed DC voltage with a third DC voltage value, said first and second output terminals adapted for electrical interconnection with the first and second terminals of said DC motor, said third output terminal adapted for electrical interconnection with the fourth terminal of said DC motor;
• means for determining the armature voltage of the armature winding of said DC motor;
• means for determining the field current of the field winding of said DC motor;
• means for determining the armature current of the armature winding of said DC motor;
• means for calculating the speed of said DC motor from the determined armature voltage, the determined field current and the determined armature current;
• means for providing a speed reference;
• and
• means for controlling said DC/DC converter responsive to the calculated speed of said DC motor and said speed reference in order to independently control the first, second and third DC voltage values;
• wherein K is a motor constant of said DC motor;
• wherein VA is the determined armature voltage of said DC motor;
• wherein IF is the determined field current of said DC motor;
• wherein IA is the determined armature current of said DC motor;
• wherein the armature of said DC motor has a resistance, RA;
• and wherein said means for calculating the speed of said DC motor calculates said speed as a function of:
• ( V A - I A ⁢ R A K ⁢ ⁢ I F ) .

A reversible direct current (DC) motor drive for a DC motor having a speed, said DC motor including first and second terminals for an armature winding having an armature voltage and an armature current, said DC motor also including third and fourth terminals for a field winding having a field voltage and a field current, said DC motor drive comprising:

• a DC/DC converter having a DC input and at least three output terminals, said output terminals including a first output terminal having a first pulsed DC voltage with a first DC voltage value, a second output terminal having a second pulsed DC voltage with a second DC voltage value, and a third output terminal having a third pulsed DC voltage with a third DC voltage value, said first and second output terminals adapted for electrical interconnection with the first and second terminals of said DC motor, said third output terminal adapted for electrical interconnection with the fourth terminal of said DC motor;
• means for determining the armature voltage of the armature winding of said DC motor;
• means for determining the field current of the field winding of said DC motor;
• means for determining the armature current of the armature winding of said DC motor;
• means for calculating the speed of said DC motor from the determined armature voltage, the determined field current and the determined armature current;
• means for providing a speed reference;
• and
• means for controlling said DC/DC converter responsive to the calculated speed of said DC motor and said speed reference in order to independently control the first, second and third DC voltage values;
• wherein said DC/DC converter includes four output terminals, including the first output terminal, the second output terminal, the third output terminal and a fourth output terminal;
• wherein said first and second output terminals are adapted for electrical connection with the armature winding of said DC motor;
• and wherein said third and fourth output terminals are adapted for electrical connection with the field winding of said DC motor.

A reversible direct current (DC) motor drive for a DC motor having a speed and a torque, said DC motor including first and second terminals for an armature winding and third and fourth terminals for a field winding, said DC motor operable in at least one of four quadrants including positive speed and positive torque, positive speed and negative torque, negative speed and negative torque, and negative speed and positive torque, said DC motor drive comprising:

• at least two input terminals adapted to receive a DC voltage, said input terminals including first and second input terminals;
• first and second switches electrically connected in series between said first and second input terminals;
• first and second transistors electrically connected in series between said first and second input terminals;
• first and second diodes electrically connected in parallel with said first and second transistors, respectively, said first and second transistors having a first polarity, said first and second diodes having an opposite second polarity;
• a third diode;
• a third transistor electrically connected in series with said third diode, said third transistor having the first polarity, said third diode having the opposite second polarity;
• at least three output terminals, said output terminals including a first output terminal electrically interconnected with a first node between said first and second switches, a second output terminal electrically interconnected with a second node between said first and second transistors, and a third output terminal electrically interconnected with a third node between said third diode and said third transistor;
• means for determining a voltage between said first and second output terminals;
• means for determining a first current and a second current, said first current flowing between one of said first node and said first output terminal, said second node and said second output terminal, and said third node and said third output terminal, and said second current flowing between a different one of said first node and said first output terminal, said second node and said second output terminal, and said third node and said third output terminal;
• means for calculating the speed of said DC motor from the determined voltage, the determined first current and the determined second current;
• and
• means for controlling said first, second and third transistors and responding to the calculated speed of said DC motor to provide operation of said DC motor in said four quadrants and independent control of said first and second currents.