Electronic revenue meter with automatic service sensing
View Patent ↗An integral electronic revenue meter system diagnostics package including a microprocessor, storage memory, preselect series of system diagnostic tests, and recording any results which exceed predefined programmable thresholds, and display means for displaying error and/or diagnostic messages identifying selected diagnostic data and/or errors discovered in the meter tests during a predefined period is included as part of an electricity revenue meter of the type used for collecting metering data for a utility which uses such data for billing purposes. The system automatically senses the type of electrical service in which the revenue meter is installed when the revenue meter is installed in a socket at the customer's premises.
1. A method of determining the electrical service type provided by an electrical service provider, comprising the steps of:
configuring an apparatus to connect to a polyphase electrical service wherein each phase of said polyphase electrical service has a voltage component and a current component;
configuring said apparatus with at least one analog-to-digital converter interfaced to selected phases of said electrical service, said analog-to-digital converter configured to provide digital representations of said voltage component and said current component;
configuring said apparatus with memory for storing reference information relating to at least phase for at least one type of electrical service wherein said reference information includes at least an ideal current angle for said at least one phase of said polyphase electrical service;
configuring said apparatus with a microprocessor interfaced with said at least one analog-to-digital converter and said memory;
configuring said microprocessor to designate one phase of said polyphase electrical service as the base phase and one of the other phases of said polyphase electrical service as the test phase;
configuring said microprocessor to determine a measured power factor angle for said test phase of said polyphase electrical service;
configuring said microprocessor to determine a measured current phase angle for the current component for said test phase of said polyphase electrical service, wherein said measured current phase angle is referenced to the waveform of the current component for said base phase, wherein said measured current phase angle is determined using said digital representations; and
configuring said microprocessor to automatically determine the electrical service type to which said apparatus is connected using said measured power factor angle, said measured current phase angle and said reference information.
2. A method according to claim 1 , wherein said microprocessor is further configured to calculate at least two values from the group consisting of: (a) apparent power; (b) reactive power; and (c) active power.
3. A method according to claim 2 , wherein said measured power factor angle defines the arccosine of said active power divided by said apparent power.
4. A method according to claim 1 , wherein said microprocessor is further configured to determine a measured voltage phase angle for said at lease one phase of said polyphase electrical service using said digital representations and wherein said measured voltage phase angle is relative to said base phase.
5. A method according to claim 4 , wherein said measured power factor angle defines the difference between said measured voltage phase angle and said measured current phase angle.