Motor-generator system providing prolonged uninterrupted power supply to a load

• US 4,412,170 A
• Filed: 07/02/1981
• Issued: 10/25/1983
• Est. Priority Date: 07/02/1981
• Status: Expired due to Term

• Current Assignee: Precise Power Corporation
• Original Assignee: Precise Power Corporation
• Inventors: Roesel, John F. Jr.
• Primary Examiner(s): Hickey, R. J.
• Application Number:
  US06/279,880
• Time in Patent Office: 845 Days
• Field of Search: 322/4, 322/29, 322/32, 322/100, 322/9, 307/64, 307/68
• US Class Current: 322/4
• CPC Class Codes: H02J 9/066 characterised by the use of dynamo-electric machines H02J9/08 takes precedence
• CPC Class Codes: H02K 7/025 for power storage
• CPC Class Codes: Y02E 60/16 Mechanical energy storage, e.g. flywheels or pressurised fluids

Abstract

The present invention relates to a generator system connected to an external A.C. power source for supplying electrical A.C. power to a load for prolonged periods when the external electrical A.C. power source fails. The system comprises a main A.C. generator unit capable of generating an A.C. potential at a selected frequency and voltage for the load, and an auxiliary A.C. generator is connected to the main generator for generating A.C. at a high frequency. This high frequency A.C. is conveyed to a relatively small high speed motor and flywheel unit in a sealed chamber, which unit at full speed can store large amounts of rotational kinetic energy. The high speed motor has a stator armature with a power winding and an excitation coil, and a cooperating rotor of soft magnetic material having a cylindrical surface with a layer of magnetizable permanent magnet material thereon. When energized with the high frequency A.C., the power winding causes the rotor to rotate as a hysteresis motor. When the external electrical A.C. power source fails, the excitation coil is energized with high frequency A.C. to magnetize the layer of permanent magnet material into a pattern of north and south magnetic poles which will enable the rotational kinetic energy of the rotor and flywheel to generate high frequency A.C. of constant frequency in the power winding which is supplied to the auxiliary generator to cause it to function as a synchronous motor to drive the main A.C. generator so that it will keep on producing the A.C. potential to the load.

Claims

1. In a generator system connected to and cooperating with an external A.C. power source which is subject to faults, failures and outages, in order to supply A.C. power of a substantially constant frequency and voltage to a load without interruptions and including prolonged periods when electrical power from the external A.C. source fails, in combination:

(a) a rotatable generator system connectable to the external A.C. power source, comprising (1) a main A.C. generator which can generate and supply to the load a main A.C. potential at a selected substantially constant frequency and voltage while the main A.C. generator is rotating in a given RPM range and (2) an auxiliary high frequency A.C. generator rotatably connected to the main A.C. generator, the auxiliary A.C. generator capable of functioning as a synchronous motor when supplied high frequency A.C. potential from an outside source, and

(b) the auxiliary generator being electrically connected to a high speed motor and flywheel unit in a sealed chamber to supply the high frequency A.C. to the high speed motor to cause it to rotate at a high speed whereby the motor and flywheel unit can store large amounts of rotational kinetic energy at full speed, a low windage-loss atmosphere being present in the sealed chamber, the high speed motor comprising a motor having a field core of soft magnetic material with a circular cylindrical surface having a layer of magnetizable permanent magnet material thereon, and a slotted stator armature of soft magnetic material having a cylindrical surface complementary to and juxtaposed with the layer of magnet material on the field core, an excitation coil in slots in the armature whereby when A.C. current of a selected frequency is passed through the excitation coil it will induce in the juxtaposed layer of permanent magnet material in the rotating field core a pattern of north and south magnetic poles, and power windings in other slots in the stator armature, the power windings being connected to the auxiliary A.C. generator to receive the high frequency A.C. potential therefrom to cause the high speed motor to operate as hysteresis motor, and upon failure of the external electrical A.C. power, the excitation coil can be energized with a selected constant frequency A.C. current to induce the pattern of north and south magnetic poles in the layer of magnetizable permanent magnet material and thereby cause the power windings in the armature to generate high frequency A.C. of a constant frequency as the rotational kinetic energy of the rotor and flywheel cause the rotor and the stator to rotate with respect to each other, and when this last high frequency A.C. is supplied to the auxiliary generator it will be caused to operate as a synchronous motor to drive the main A.C. generator for a prolonged period of time in the given RPM range and thus generate A.C. potential of the selected frequency and voltage to be supplied to the load.

2. In the generator system of claim 1 wherein an A.c. driving motor supplied electrical power from the external A.C. electrical power source drives the main generator in a given RPM range which generates and supplies to the load a main A.C. potential at a selected frequency and voltage, and the A.C. motor also driving the auxiliary A.C. generator which generates A.C. potential at a high frequency, the auxiliary generator capable of functioning as a synchronous motor when supplied A.C. potential from an outside source, and means for conveying the high frequency A.C. to the high speed motor.

3. The generator system of claim 2, wherein control means are provided for connecting the A.C. driving motor to the external electrical power source to enable the generator system to be brought up to its given RPM range so that it will generate the main A.C. potential and the auxiliary A.C. generator to generate the high frequency A.C., and means to supply the high frequency A.C. to the high speed motor to bring it up to its full speed;

and, upon failure of the external electrical source, the control means will disconnect the driving motor from the failed external electrical power source, and concurrently enables the energizing of the excitation coil with the selected A.C. current to induce the pattern of north and south magnetic poles in the layer in the field core whereby the power windings in the armature will generate high frequency A.C. of a constant frequency during the relative rotation of the stator armature with respect to the rotor, and supplying the high frequency A.C. so generated to the auxiliary generator which thereupon functions as a synchronous motor to drive the main generator in the given RPM range so as to keep on supplying to the load the main A.C. potential of the selected frequency and voltage, the rotational kinetic energy of the high speed motor and flywheel unit being sufficient to keep the main generator operating in the given RPM range for a prolonged period of time, and upon return of the external A.C. power source, the control means will simultaneously reconnect the driving motor to the external A.C. power source and stop energizing of the excitation coil with high frequency A.C.

4. The generator system of claim 2, wherein the driving motor is a synchronous motor.

5. The generator system of claim 1, wherein the low windage-loss atmosphere in the sealed chamber is hydrogen gas.

6. The generator system of claim 1, wherein the low windage-loss atmosphere in the sealed chamber is a vacuum.

7. The generator system of claim 1, wherein the external A.C. power source is connected in a circuit through a main control means to supply A.C. power to both the load and to the main generator, the external A.C. power causing the main generator to function as a motor whereby to drive the auxiliary generator to cause it to generate high frequency A.C. potential which is supplied to the high speed motor and flywheel unit to bring it up to full speed, and upon fault or failure of the external A.C. power source, the main control disconnects the circuit to the external A.C. power source and the control means causes selected high frequency A.C. to be supplied to the excitation coil so that high frequency A.C. is generated by the high speed motor and flywheel unit and supplied to the auxiliary generator to cause it to function as a motor to drive the main A.C. generator in the given RPM range to generate and supply main A.C. potential to the load without any interruption.

8. the generator system of claim 7 wherein an isolating and regulating transformer is interposed in the circuit from the main control means to the load.