Niagara Mohawk Power Corporation

Cuisinarts, Inc.

William R Smith-Vaniz

Roosevelt A Fernandes

Richard L Sieron

John E Burbank, Iii

John R Montgomery

Carl G Sontheimer

A self contained sensor module mounted on a power transmission line. The module is capable of measuring various parameters such as line current, voltage, conductor temperature and ambient temperature. The parameter values are processed by sensor electronics which digitize and periodically transmit the values to a ground receiver. The module power supply is coupled to the transmission line conductor by a transformer. The line conductor extends through a magnetic core in the module housing. A secondary shunt magnetic core is provided to limit induction of high voltages as a result of excess current flowing through the transmission line conductor.

Power supply magnetic shunt for transmission line sensor module

Self contained radio transmitting modules are mounted on power conductors at various places along electrical transmission lines. The modules are capable of measuring current, voltage, frequency and power factor (or the Fourier components thereof), the temperature of the conductor and the temperature of the ambient air. Up to fifteen modules may transmit on a single channel to a single local receiver. Each module transmits at intervals which are an integral number. The intervals between transmissions of all modules do not have a common factor and the average interval is the desired transmission rate.

Apparatus for data transmission from multiple sources on a single channel

A self contained hot stick mounted radio transmitting module may be permanently mounted on or temporarily pushed against the power conductor of an electrical transmission line. The module is capable of measuring the potential difference between the conductor and ground. The module digitizes and transmits the value of the potential difference to a ground receiver. The module is donut shaped and opens like a pair of jaws. The contact with the power line is accomplished via a resilient conductive elastomer that covers the surfaces in contact with the power conductor. The potential difference between ground and the power conductor is measured with an operational amplifier in an integrating configuration to convert the leakage current from the module to ground into a proportional voltage from a low impedance source. The integrator outputs a voltage proportional to the current flowing into the equivalent capacitance formed by the outer surface of the module and ground. The current is generated by the voltage difference between the power conductor and ground. The power conductor is engaged by a pair of jaws inserts comprising two concentric conducting rings separated by a thin insulating layer forming a large capacitor. The electronic components within the unit are protected by a signal conditioning network to preclude destruction of components in the event of lightning strikes or other overvoltage conditions.

Line mounted apparatus for measuring line potential

A 'hot-stick' mountable sensor module for attachment and removable from a live power transmission line. A tool is insertable into a mounted module to attach the module to the tool and permit removal of the module from the line.

Tool for mounting a sensor module on a live power transmission line

A friction braking system located entirely inside an induction motor of an appliance quickly stops rotation of the rotor in the appliance motor, for example such as a food processor, whenever the A.C. electrical power is turned off. Thus, rotation of any tool being operated in the appliance is quickly stopped, whenever the electrical power is interrupted. The rotor in the induction motor is axially slidably mounted on the motor shaft and is keyed to the shaft for permitting axial shifting displacement of the rotor relative to the stator while preventing any angular displacement of the rotor relative to the shaft. Consequently, the rotor and shaft always turn and stop as a function unit. A friction brake lining is affixed within the motor housing offset from the axis of the motor shaft as far as practicable. A disc brake mounted onto the rotor has an annular friction braking surface positioned for engagement against the brake lining. The rotor is arranged for an axial thrust to shift the rotor in an axial direction away from its normal operating position aligned with the stator, whenever the electrical power is interrupted, thereby applying friction braking action quickly and at a relatively large moment arm as compared with the radius of the rotor for effective braking. The brake disc may include motor-cooling fan blades. An inverted V-shaped brake surface configuration is also shown for enhancing braking action.

Friction braking system and apparatus for appliance induction motor drive

Self contained radio transmitting state estimator modules are mounted on power conductors on both sides of power transformers in electrical substations and on power conductors at various places along electrical transmission lines. They are electrically isolated from ground and all other conductors. These modules are capable of measuring current, voltage, frequency and power factor (or the fourier components thereof) the temperature of the conductor, and the temperature of the ambient air. The modules transmit these parameters to local receivers. The receivers are connected by an appropriate data transmission link, to a power control center which allows determination of the state of the power system. The module measures the Fourier components of voltage and current over a number of cycles and transmits the components to the local receiver.

Apparatus for power measuring and calculating Fourier components of

Self contained radio transmitting state estimator modules are mounted on power conductors on both sides of power transformers in electrical substations and on power conductors at various places along electrical transmission lines. They are electrically isolated from ground and all other conductors. These modules are capable of measuring current, voltage, frequency and power factor (or the fourier components thereof) the temperature of the conductor, and the temperature of the ambient air. The modules transmit these parameters to local receivers. The receivers are connected by an appropriate data transmission link, to a power control center which allows determination of the state of the power system. Appropriate control signals are transmitted back to the electrical switchgear of the system to bring it to the appropriate optimum state. Direct local control may also be effected, for example, the prevention of overloading a transformer. A 'donut' state estimator module comprises a novel hot stick operated hinge clamp and a novel voltage sensor which measures the current between an isolated capacitor plate and ground. The donut measures the fourier components of voltage and current over a number of cycles and transmits the components to the local receiver. The local receiver derives the desired electrical measurements such as voltage, current, power factor, power, and reactive power and transmits them to local or remote control stations. Up to 15 donut modules may transmit on a single channel to a single local receiver. Each transmits at intervals which are an integral number. The intervals between transmissions of all donuts do not have a common factor and the average interval is the desired transmission rate. Each donut uses the zero crossover of current of its conductor to establish its transmission interval. The system is self-calibrating using known reference signals within the donut module.

Apparatus for measuring the potential of a transmission line conductor

Self contained radio transmitting state estimator modules are mounted on power conductors on both sides of power transformers in electrical substations and on power conductors at various places along electrical transmission lines. They are electrically isolated from ground and all other conductors. These modules are capable of measuring current, voltage, frequency and power factor (or the Fouier components thereof), the temperature of the conductor and the temperature of the ambient air. The modules transmit these parameters to local receivers. The receivers are connected by an appropriate data transmission link to a power control center which allows determination of the state of the power system. Appropriate control signals are transmitted back to the electrical switchgear of the system to bring it to the appropriate optimum state. Direct local control may also be effected, for example, the prevention of overloading a transformer.

System and apparatus for monitoring and control of a bulk electric power

A self contained hot stick mounted radio transmitting module may be temporarily pushed against the power conductor of an electrical transmission line. The module is capable of measuring the temperature of the conductor, and the temperature of the ambient air. It may also measure the electrical potential of the conductor. An alternative module is also capable of measuring current, potential, frequency and power factor (or the Fourier components thereof). The modules transmit these parameters to a local receiver where the data may be displayed. The receiver also may be connected by an appropriate data transmission link, to a power control center. The modules are donut shaped and open like a pair of jaws. One or more spring loaded temperature probes are located such that they may be pushed against a power line when a 'donut' is mounted to a hot stick with the jaws open. Power to an open module is supplied by a battery. Power to a closed module, mounted on a conductor, may be supplied by the battery or by power derived from the conductor. A donut may be left on the power line for an indefinite time and the hot stick removed, or instantaneous measurements may be made with the hot stick attached, and the module then immediately removed. The temperature probe of the present invention comprises a pair of concentric spring loaded tubes. A beryllia insert is mounted between a temperature sensor and the power conductor.

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Darien, CT, United States of America

William R Smith-Vaniz