Motor control system for electrically powered vehicles

Claim 1

A CONTROL SYSTEM FOR AN ELECTRICALLY POWERED SELFPROPELLED VEHICLE COMPRISING IN COMBINATION: AN INTERNAL COMBUSTION ENGINE; A DIFFERENTIAL COMPOUND DIRECT CURRENT GENERATOR HAVING A SERIES FIELD, A SHUNT FIELD AND OUTPUT TERMINALS; A GENERATOR EXCITER HAVING A FIELD WINDING; A MOTOR EXCITER HAVING A FIELD WINDING; MEANS MECHANICALLY COUPLING SAID GENERATOR AND EXCITERS TO SAID ENGINE; A PLURALITY OF ELECTRIC WHEEL MOTORS OF THE DIRECT CURRENT CUMULATIVE COMPOUND TYPE, EACH HAVING A SHUNT FIELD, A SERIES FIELD, AND INPUT TERMINALS; A PAIR OF MAIN CONDUCTOR TERMINALS; MEANS CONNECTING SAID GENERATOR OUTPUT TERMINALS AND THE RESPECTIVE INPUT TERMINALS OF SAID MOTORS IN PARALLEL TO SAID MAIN CONDUCTOR TERMINALS; RELAY ACTUATED CONTACT MEANS FOR REVERSING THE POLARITY OF THE SERIES FIELDS OF SAID MOTORS; POLARITY SENSING MEANS FOR ACTUATING SAID CONTACT MEANS TO REVERSE SAID MOTOR SERIES FIELDS RESPONSIVE TO A CHANGE OF VOLTAGE POLARITY AT SAID MAIN CONDUCTOR TERMINALS; MEANS FOR SUPPLYING DIRECT CURRENT VOLTAGE OF SELECTABLE POLARITY AND MAGNITUDE TO SAID GENERATOR EXCITER FIELD WINDING; MEANS FOR SUPPLYING A DIRECT CURRENT VOLTAGE OF PREDETERMINED MAGNITUDE IN SERIES WITH SAID MOTOR EXCITER FIELD WINDING; MEANS FOR SUPPLYING THE VOLTAGE AT SAID MAIN CONDUCTOR TERMINALS THROUGH A RELAY ACTUATED REVERSING SWITCH IN SERIES WITH SAID VOLTAGE OF PREDETERMINED MAGNITUDE AND IN BUCKING RELATION THERETO; MEANS ASSOCIATED WITH SAID POLARITY SENSING MEANS FOR ACTUATING SAID REVERSING SWITCH RESPONSIVE TO A CHANGE OF POLARITY AT SAID MAIN CONDUCTOR TERMINALS; A DYNAMIC BRAKING CONTROLLER INCLUDING A VARIABLE RESISTANCE CONNECTED IN SERIES WITH SAID MOTOR EXCITER FIELD WINDING AND HAVING AN OFF POSITION; A DYNAMIC BRAKING RELAY HAVING FIRST AND SECOND NORMALLY CLOSED CONTACTS, AND FIRST AND SECOND NORMALLY OPEN CONTACTS; CONDUCTORS CONNECTING SAID FIRST NORMALLY CLOSED CONTACT IN SHUNT WITH SAID VARIABLE RESISTANCE; CONDUCTORS CONNECTING SAID SECOND NORMALLY CLOSED CONTACT IN SERIES WITH SAID GENERATOR EXCITER FIELD EXCITATION SUPPLY; A SERIES FIELD REDUCING RELAY ASSOCIATED WITH EACH SAID MOTOR AND HAVING A NORMALLY OPEN CONTACT AND ENERGIZING MEANS; CONDUCTOR MEANS CONNECTING SAID LAST MENTIONED NORMALLY OPEN CONTACT IN SHUNT WITH MAJOR PORTION OF THE TURNS OF THE RESPECTIVE MOTOR SERIES FIELD; CONDUCTOR MEANS CONNECTING SAID FIRST NORMALLY OPEN CONTACT IN SERIES WITH SAID SERIES FIELD REDUCING RELAY ENERGIZING MEANS; A DYNAMIC BRAKING RESISTANCE GRID; CONDUCTOR MEANS CONNECTING SAID SECOND NORMALLY OPEN CONTACT IN SERIES WITH SAID RESISTANCE GRID ACROSS SAID MAIN CONDUCTOR TERMINALS; ENERGIZING MEANS FOR SAID DYNAMIC BRAKING RELAY; AND SWITCH MEANS OPERATIVE RESPONSIVE TO MOVEMENT OF SAID DYNAMIC BRAKING CONTROLLER FROM ITS OFF POSITION FOR CLOSING THE CIRCUIT OF SAID DYNAMIC BRAKING RELAY ENERGIZING MEANS.