Energy recovery system for cyclic drives

• US 4,733,146 A
• Filed: 12/15/1986
• Issued: 03/22/1988
• Est. Priority Date: 11/09/1984
• Status: Expired due to Fees

• Current Assignee: Reliance Electric Company (ABB Limited)
• Original Assignee: Reliance Electric Company (ABB Limited)
• Inventors: Hamby, Russell S.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): IP, SHIK LUEN PAUL
• Application Number:
  US06/942,027
• Time in Patent Office: 463 Days
• Field of Search: 318/258-263, 318/269, 318/331, 318/341, 318/139, 318/345 R, 318/345 C, 318/345 CA, 318/345 B, 318/345 AB, 318/345 D, 318/345 F, 318/345 G , 318/356, 318/357, 318/358, 318/364, 318/374, 318/375, 318/376, 318/377, 318/385, 318/387, 318/391, 318/392, 318/393, 318/410, 318/408, 318/405, 318/404, 318/406 , 318/407, 318/400, 318/417, 318/416, 318/430, 318/431, 318/432, 318/433, 318/434, 318/341, 318/803, 318/807, 318/806, 363/37, 363/48, 363/34, 363/87, 363/129, 363/124, 363/138, 187/104-120
• US Class Current: 388/847
• CPC Class Codes: H02P 23/20 Controlling the acceleration or deceleration
• CPC Class Codes: Y10S 388/91 Operational/differential amplifier
• CPC Class Codes: Y10S 388/915 Sawtooth or ramp waveform generator
• CPC Class Codes: Y10S 388/916 Threshold circuit
• CPC Class Codes: Y10S 388/917 Thyristor or scr

Abstract

A system is disclosed for recovering and storing the energy generated by an electrical motor during deceleration so as to be available for use when the motor is subsequently accelerated. The system utilizes a capacitor for storing the energy produced by voltage regeneration of the motor when decelerating. A two-quadrant regulator, connected between a three-phase rectifier and a four-quadrant SCR regulator, controls the charging and discharging of the capacitor so that the energy stored therein is proportional to the energy required to accelerate the motor and load to the maximum rotational velocity required.

Claims

1. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, and means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith.

2. The system as defined in claim 1 wherein said capacitance means is capable of storing electrical energy equal to the total maximum rotational kinetic energy of the motor and any load associated therewith.

3. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for producing a reference voltage for said capacitance means, and means for comparing said reference voltage to said instantaneous terminal voltage of said capacitance means, said comparing means producing an output signal representative of the difference between said reference voltage and said instantaneous terminal voltage of said capacitance means, said output signal being utilized to control said duty cycle of said energy transfer allowing means.

4. A system for recovering the electrical energy produced by an electric motor during deceleration or reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for producing a reference voltage for said capacitance means, said reference voltage being proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, and means for comparing said reference voltage to said instantaneous terminal voltage of said capacitance means, said comparing means producing an output signal representative of the difference between said reference voltage and said instantaneous terminal voltage of said capacitance means, said output signal being utilized to control said duty cycle of said energy transfer allowing means.

5. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, and means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means comprising switching means which allows said capacitance means to receive the electrical energy produced by the motor during deceleration and permits the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said switching means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith.

6. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means comprising switching means which allows said capacitance means to receive the electrical energy produced by the motor during deceleration and permits the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said switching means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for producing a reference voltage for said capacitance means, and means for comparing said reference voltage to said instantaneous terminal voltage of said capacitance means, said comparing means producing an output signal representative of the difference between said reference voltage and said instantaneous terminal voltage of said capacitance means, said output signal being utilized to control said duty cycle of said switching means.

7. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the instantaneous rotational kinetic energy of the motor and any load associated therewith, means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said energy transfer allowing means comprising switching means which allows said capacitance means to receive the electrical energy produced by the motor during deceleration and permits the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor, said switching means having a duty cycle that is varied causing the instantaneous terminal voltage of said capacitance means to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, means for producing a reference voltage for said capacitance means, said reference voltage being proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the instantaneous rotational kinetic energy of the motor and any load associated therewith, and means for comparing said reference voltage to said instantaneous terminal voltage of said capacitance means, said comparing means producing an output signal representative of the difference between said reference voltage and said instantaneous terminal voltage of said capacitance means, said output signal being utilized to control said duty cycle of said switching means.

8. A system for recovering the electrical energy produced by an electric motor during deceleration for reuse during subsequent acceleration of the motor comprising capacitance means for storing the electrical energy produced by the electric motor during deceleration, an inductance and a resistance electrically connected to said capacitance means, said inductance, resistance and capacitance means having electrical properties approximating the electrical properties of the motor, means for controlling the charging and discharging of said capacitance means permitting the amount of electrical energy stored therein to be proportional to the difference between the total maximum rotational kinetic energy of the motor and any load associated therewith and the total instantaneous rotational kinetic energy of the motor and any load associated therewith, and means for allowing the transfer of said electrical energy from said capacitance means to the motor for reuse during the subsequent acceleration of the motor.