摘要:
A universal electronic energy meter for measuring electrical energy usage of a circuit having a 4-wire service is disclosed. The universal meter is operable with both 4-wire wye and 4-wire delta services without modification to the meter's hardware or software. The universal meter is further operable over a wide range of standard service voltages that are supplied in connection with 4-wire services. The universal meter includes a voltage divider network that senses the line voltages from the circuit and scales the line voltages to a voltage suitable for processing by the meter. The scaled voltage has a maximum peak-to-peak voltage irrespective of the particular standard service supplying the electrical energy to the circuit, and therefore, the voltage divider network is not reconfigured to accommodate a wide range of service voltages. The voltage divider network includes resistive dividers that scale the line voltage to provide a linear voltage with minimal phase shift. The universal meter also includes a power supply that is also operable over a wide range of service voltages. The power supply supplies a regulated fixed supply voltage used by the meter for processing functions carried out by the meter independent of the type of 4-wire service supplying the electrical energy to the circuit.
摘要:
Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering values. The processing unit is operable in response to supply voltages. A power supply, connected to receive the undivided voltage component, generates the supply voltages over the wide dynamic range. It is especially preferred for the power supply to include a transformer having first, second and third windings, wherein the undivided voltage component is provided to the first winding and wherein the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current in response to a control signal. A control member generates the control signal in response to the output of the power supply. It is also preferred for the control signal to disable the switch member. It is further preferred for the power supply to include a voltage blocking clamp, connected to the transformer for blocking the voltage applied to the transformer. It is still further preferred for an oscillator to be used to generate an oscillating signal for switching the switching member ON and OFF so that the switching member is provided a substantially constant OFF time.
摘要:
A power supply comprises a rectifier, a transformer, a switching member, a controller and a voltage blocking clamp. A power supply can receive an alternating current (AC) input voltage having any magnitude within a wide range of AC input voltage magnitudes and can produce from any such AC input voltage magnitude a direct current (DC) output voltage. The voltage blocking clamp comprises at least one transistor connected between the rectifier and the transformer and switching member that limits the amount of rectified AC input voltage applied to the transformer and switching member to a predetermined amount when the rectified input voltage exceeds that predetermined amount. When the rectified input voltage exceeds the predetermined amount, the amount of the rectified input voltage above the predetermined amount is applied to the at least one transistor instead of the transformer and switching member.
摘要:
Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering values. The processing unit is operable in response to supply voltages. A power supply, connected to receive the undivided voltage component, generates the supply voltages over the wide dynamic range. It is especially preferred for the power supply to include a transformer having first, second and third windings, wherein the undivided voltage component is provided to the first winding and wherein the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current in response to a control signal. A control member generates the control signal in response to the output of the power supply. It is also preferred for the control signal to disable the witch member. It is further preferred for the power supply to include a voltage blocking clamp, connected to the transformer for blocking the voltage applied to the transformer. It is still further preferred for an oscillator to be used to generate an oscillating signal for switching the switching member ON and OFF so that the switching member is provided a substantially constant OFF time.
摘要:
An apparatus for metering electrical energy over a predetermined range of voltages within a single meter. The meter includes a divider network for dividing the voltage to generate a divided voltage. The divided voltage is substantially linear with minimal phase shift over the wide dynamic range. A processing unit processes the divided voltage and a current component to determine metered electrical power. A power supply receives the voltage component and generates a supply voltage from the voltage component over the predetermined range to power the processing unit. The power supply may include a transformer having first, second and third windings, so that the voltage component is provided to the first winding and the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current through the first winding. The switch member is operable in response to a control signal, which disables the switch member, that is generated by a controller in response to the output of the power supply.
摘要:
An electronic energy meter for use with a 3-wire delta service having a resistive voltage divider for sensing and scaling the line voltages is disclosed. The resistive voltage divider includes three resistive dividers, one being associated with each phase of the electrical energy being metered. Each resistive divider includes a current limiter for reducing the current into the meter to a safe level when the meter electronics are operating at an elevated level, and a resistor for scaling the line voltage to a predetermined maximum peak-to-peak value. The scaled voltage that is generated has minimal phase shift, and therefore, does not require phase shift compensation prior to processing by a processing system of the electronic meter.
摘要:
Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering values. The processing unit is operable in response to supply voltages. A power supply, receives an undivided voltage component and generates supply voltages over the wide dynamic range. It is especially preferred for the power supply to include a transformer having first, second and third windings, wherein the undivided voltage component is provided to the first winding and wherein the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current in response to a control signal. A control member generates the control signal in response to the output of the power supply. It is also preferred for the control signal to disable the switch member. It is further preferred for the power supply to include a voltage blocking clamp, connected to the transformer for blocking the voltage applied to the transformer. It is still further preferred for an oscillator to be used to generate an oscillating signal for switching the switching member ON and OFF so that the switching member is provided a substantially constant OFF time.
摘要:
An electronic energy meter senses input voltage and current signals and processes the input voltage and current signals to generate measurements of multiple types of power. The meter comprises a processing system for selecting one of the multiple types of power and defining the same as the selected type of power. The processing system also generates a pulsed test signal representative of a magnitude of a measurement of the selected type of power for testing the operation of the meter. The meter further comprises a communications interface coupled to the processing system for transmitting the pulsed test signal from the meter and for receiving signals from sources external to the meter. Selection of one of the multiple types of power can be achieved by the meter receiving, via the communications interface and from a source external to the meter, a communications command identifying a selected one of the various types of power. The communications interface may comprise an optical communications port.
摘要:
Methods and apparatus for electronically displaying metered electrical energy are disclosed. A first processor receives voltage and current signals, determines electrical energy and generates an energy signal representative of the electrical energy determination. A second processor receives the energy signal and generates a display signal representative of electrical energy information. A display receives the display signal and displays the electrical energy information. In a first embodiment, it is preferred for the first processor to determine units of electrical energy and the rate at which the units are determined. The second processor generates a display signal representative of the units and the rate. The second processor may also generate a disk signal representative of an equivalent rate of disk rotation in relation to the rate at which the units are determined and energy flow direction information for display. A converter may also be provided for converting an electrical output signal to light. The second processor, connected to the converter, generates the electrical output signal in response to the energy signals, wherein the output signal includes a multiplexed arrangement of the energy signals.
摘要:
A system for determining the service type to which an energy meter having meter elements is connected. The system includes a memory for storing reference information relating to different service types. The system determines which meter elements of the energy meter are active, and then determines relative phase angles and phase voltages of the meter elements. The relative phase angles are determined in to be in an ABC or a CBA rotation. Power quality monitoring is used in determining the phase voltages. The relative phase angles and phase voltages are compared to the reference information to determine the service type. The reference information includes services and scaling information, a nominal service voltage, a programmable potential indicator threshold, and a maximum and a minimum tolerance with respect to the nominal service voltage.