Load-side voltage sensing in a power meter
A load-side voltage detection module for a metrology device includes a plurality of first resistors electrically coupled to a first load-side terminal, the first resistors being in series, a plurality of second resistors electrically coupled to a second load-side terminal, the second resistors being in series, a voltage divider electrically coupled between a first line-side terminal and a second line-side terminal, the voltage divider creating a reference voltage for the load-side voltage detection module, and a pulse generator to generate a pulse based on detection of voltage, the pulse indicating a voltage on at least one of the first load-side terminal or the second load-side terminal, above at least one threshold.
1. A load-side voltage detection module for a metrology device comprising:
a plurality of first resistors electrically coupled to a first load-side terminal, the first resistors being in series;
a plurality of second resistors electrically coupled to a second load-side terminal, the second resistors being in series and having resistance values different with respect to the first resistors; and
a pulse generator including:
a first transistor electrically coupled to at least one of the first resistors; and
a second transistor electrically coupled to at least one of the second resistors, the first transistor and the second transistor configured to generate a pulse on an isolated output.
2. The load-side voltage detection module of claim 1 , further comprising a voltage divider electrically coupled between a first line-side terminal and a second line-side terminal, the voltage divider configured to create a reference voltage for the load-side voltage detection module.
3. The load-side voltage detection module of claim 2 , wherein the voltage divider is configured to create a virtual ground.
4. The load-side voltage detection module of claim 1 , wherein the pulse generator is configured to generate the pulse based on detection of a voltage at at least one of the first load-side terminal or the second load-side terminal, the pulse indicating the voltage on at least one of the first load-side terminal or the second load-side terminal is above a threshold.
5. The load-side voltage detection module of claim 1 , wherein the load-side voltage detection module is configured to detect whether a first voltage at the first load-side terminal and a second voltage at the second load-side terminal are in phase with respect to one another.
6. The load-side voltage detection module of claim 1 , further comprising a load-side voltage disconnect switch electrically coupled to the load-side voltage detection module.
7. The load-side voltage detection module of claim 1 , wherein the pulse generator includes:
a first diode;
a second diode in series with the first diode;
a capacitor in parallel with the first diode;
the first transistor;
the second transistor in series with the first transistor, the first transistor and the second transistor being in parallel with the capacitor; and
an optoisolator electrically coupled to the second transistor, the optoisolator generating the pulse on the isolated output.
8. The load-side voltage detection module of claim 1 , wherein the pulse is output to an application specific integrated circuit (ASIC) of the metrology device.
9. A metrology device comprising:
a load-side voltage detection module, the load-side voltage detection module including:
a plurality of first resistors electrically coupled to a first line-side terminal, the first resistors being in series;
a plurality of second resistors electrically coupled to a second line-side terminal, the second resistors being in series; and
a pulse generator including:
a first transistor electrically coupled to at least one of the first resistors; and
a second transistor electrically coupled to at least one of the second resistors, the first transistor and the second transistor configured to generate a pulse on an isolated output.
10. The metrology device of claim 9 , further comprising a voltage divider electrically coupled between the first line-side terminal and the second line-side terminal, the voltage divider being configured to create a reference voltage for the load-side voltage detection module.
11. The metrology device of claim 9 , wherein the pulse generator includes:
a first diode;
a second diode in series with the first diode;
a capacitor in parallel with the first diode;
wherein:
the second transistor is in series with the first transistor, the first transistor and the second transistor being in parallel with the capacitor; and
an optoisolator electrically coupled to the second transistor, the optoisolator generating the pulse on an isolated output.
12. The metrology device of claim 9 , wherein the pulse generator is configured to generate the pulse based on detection of a voltage, the pulse indicating the voltage on at least one of the first line-side terminal or the second line-side terminal is above a threshold.
13. The metrology device of claim 9 , wherein the load-side voltage detection module is configured to detect whether a first voltage at a first load-side terminal and a second voltage at a second load-side terminal are in phase with respect to one another.
14. The metrology device of claim 9 , wherein a sum of values of the first resistors and a sum of values of the second resistors have different total resistance values.
15. The metrology device of claim 9 , further comprising a load-side voltage disconnect switch electrically coupled to the load-side voltage detection module.
16. The metrology device of claim 9 , wherein the pulse is output to an application specific integrated circuit (ASIC) of the metrology device.
17. A network, comprising:
a metrology device communicatively coupled within the network; and
a central office communicatively coupled to the metrology device at least in part over a power line,
wherein the metrology device includes:
a metrology unit, the metrology unit including a load-side voltage detection circuit, the load-side voltage detection circuit including:
a plurality of first resistors electrically coupled to a first load-side terminal, the first resistors being in series;
a plurality of second resistors electrically coupled to a second load-side terminal, the second resistors being in series; and
a pulse generator including:
a first transistor electrically coupled to at least one of the first resistors; and
a second transistor electrically coupled to at least one of the second resistors, the first transistor and the second transistor configured to generate a pulse on an isolated output.
18. The network of claim 17 , further comprising a voltage divider electrically coupled between a first line-side terminal and a second line-side terminal, the voltage divider configured to create a reference voltage for the load-side voltage detection circuit,
wherein:
the first resistors and the second resistors have different resistance values, and
the voltage divider is configured to create a virtual ground.
19. The network of claim 17 , wherein the pulse generator is configured to generate the pulse based on detection of a voltage, the pulse indicating the voltage on at least one of the first load-side terminal or the second load-side terminal is above a threshold.
20. The network of claim 17 , further comprising a load-side voltage disconnect switch electrically coupled to the load-side voltage detection circuit.