초록 ▼

A variable-speed constant-frequency alternator compensating for changes in speed of the prime mover by electromagnetically rotating the rotor\s magnetic poles around the rotor. If the prime mover has a rotational speed above or below that required to produce the desired output frequency, the magneti

A variable-speed constant-frequency alternator compensating for changes in speed of the prime mover by electromagnetically rotating the rotor\s magnetic poles around the rotor. If the prime mover has a rotational speed above or below that required to produce the desired output frequency, the magnetic poles rotate about the rotor in a forward or reverse direction, respectively. To connect the alternator to an external a.c. source, the alternator\s controls match its output to the precise amplitude frequency, and phase of the external source. The rotor, for each magnetic pole pair, includes three windings. Three-phase power in these windings, produces the magnetic pole pair and rotates it relative to the rotor. Each winding couples to a flopper circuit having k sets of resistances. The resistances, taken in turn, have an inverse proportionality to the magnitude of the desired sine wave for the three-phase current in the rotor\s windings. Coupling these resistances, one at a time, to a constant voltage source creates the equivalent sine wave current for the rotor\s windings. A transducer produces the same number of pulses per revolution of the rotor as the number of resistances in the flopper circuit. Insufficient or excessive rotor speed results in the counting of too few or too many pulses. The controller then induces a shifting of the flopper circuit to rotate the magnetic poles on the rotor to maintain the output frequency constant.

대표청구항 ▼

A variable-speed, predetermined frequency of x Hz., where x>0, alternating-current generating device comprising: (A) an alternator having: (1) a wound rotor with n magnetic pole pairs; and (2) a stator having n magnetic pole pairs, where n is a positive integer; (B) prime mover means, coupled to sai

A variable-speed, predetermined frequency of x Hz., where x>0, alternating-current generating device comprising: (A) an alternator having: (1) a wound rotor with n magnetic pole pairs; and (2) a stator having n magnetic pole pairs, where n is a positive integer; (B) prime mover means, coupled to said rotor, for moving said rotor at a rotational velocity of z rps., where z is a variable real number, relative to said stator; (C) transducer means, coupled to said rotor, for producing h pulses per revolution of said rotor, where h is a positive integer; (D) driving means, coupled to said transducer means and to said rotor pole pairs, for electromagnetically rotating said rotor pole pairs about said rotor at a rotational velocity of y=(x-z)/n rps. relative to said rotor, said driving means including: (1) for each of said n rotor pole pairs three windings spaced substantially equidistant about said center of rotation; (2) for each particular winding of the three particular windings of a particular pole pair, current means, coupled to said particular windings for creating an ac., sinusoidal current in each of said particular windings with a frequency of v Hz., said current in any one particular winding being 120°in phase ahead of the ac. current in one of the remaining two particular windings and 120°in phase behind the current in the other of the remaining two particular windings, said current means including for each one of said particular windings: (a) a current controller, coupled to the leads of said one particular winding, having k configurations, where k is a positive integer, and producing a predetermined magnitude of substantially steady amplitude current through said one particular winding for each of said configurations, the ratio of said magnitude of said current with said current controller in the ith configuration to said magnitude of said current with said current controller in the jth configuration, where i and j are positive integers not greater than k, substantially equals the ratio of the values of said sinusoidal wave at the phase angle positions i/k and j/k through a cycle of said wave; (b) current switching means coupled to said current controller, for switching, for each 1≤i≤k said current controller from said ith configuration to said (i+1)th configuration where the (k+1)th configuration is the first configuration; (c) current timing means, coupled to said current switching means and to said transducer means, for inducing said switching means to switch from said ith configuration to said (i+1)th configuration at an instantaneous rate equal to the absolute value of (ky) switches per second; and (d) current reversing means, coupled to said controller and said transducer for inverting the direction of the change of phase of the current in said particular three windings when y goes from positive to negative and when v goes from negative to positive.