Systems and methods for edge of network voltage control of a power grid
Systems and methods for an edge of network voltage control of a power grid are described. In some embodiments, a system comprises a distribution power network, a plurality of loads, and a plurality of shunt-connected, switch-controlled VAR sources. The loads may be at or near an edge of the distribution power network. Each of the loads may receive power from the distribution power network. The plurality of shunt-connected, switch-controlled VAR sources may be located at the edge or near the edge of the distribution power network where they may each detect a proximate voltage. Further, each of the VAR sources may comprise a processor and a VAR compensation component. The processor may be configured to enable the VAR source to determine whether to enable the VAR compensation component based on the proximate voltage and to adjust network volt-ampere reactive by controlling a switch to enable the VAR compensation component.
1. A system comprising:
a distribution power network;
a plurality of loads at an edge of the distribution power network, each load configured to receive power from the distribution power network; and
a plurality of shunt-connected, switch-controlled Volt-Ampere Reactive (“VAR”) sources, wherein each VAR source is located at or near the edge of the distribution power network, is configured to non-continuously monitor and detect a proximate voltage at or near the edge of the distribution power network, and comprises a processor and a VAR compensation component, the processor configured to enable the VAR source to determine, after a delay, whether to enable the VAR compensation component based on the proximate voltage and adjust network volt-ampere reactive by controlling a switch to enable the VAR compensation component based on the determination;
wherein the delay associated with each VAR source extends for a predetermined length of time that is not equal to the delay associated with any other of the plurality of VAR sources.
2. The system of claim 1 , wherein different delays of different members of the plurality of shunt-connected, switch-controlled VAR sources prevents infighting between at least two of the different members.
3. The system of claim 1 , wherein the delay of at least two of the plurality of shunt-connected, switch-controlled VAR sources is equal but the delay of a third of the plurality of shunt-connected, switch-controlled VAR sources is not equal.
4. The system of claim 1 , wherein the switch comprises a semiconductor switch in series with a Negative Temperature Coefficient (“NTC”) or resistor, and wherein the semiconductor switch in series with the NTC or resistor is in parallel with a relay.
5. The system of claim 4 , wherein the semiconductor switch is controlled by a first signal from the processor and the relay is controlled by a second signal from the processor, wherein the semiconductor switch controls enabling the VAR compensation component and relieves the relay of switching stress.
6. The system of claim 5 , wherein the relay conducts when the semiconductor switch is active thereby reducing semiconductor device conduction losses.
7. The system of claim 6 , wherein the semiconductor switch is configured to deactivate when the relay conducts.
8. The system of claim 1 , wherein at least two of the VAR sources are on a low voltage side of a transformer of the power distribution network.
9. The system of claim 1 , wherein the VAR compensation component comprises capacitors or inductors.
10. The system of claim 1 , wherein the determination to enable the corresponding VAR compensation component is based on a comparison of the proximate voltage point to a voltage set point.
11. The system of claim 10 , wherein at least two VAR sources comprise communication modules configured to receive the respective voltage set point.
12. The system of claim 10 , wherein each VAR source increases leading volt-ampere reactive if the voltage set point is higher than the detected proximate voltage and decreases leading volt-ampere reactive if the voltage set point is lower than the detected proximate voltage.
13. The system of claim 10 , wherein the communication module is configured to update the voltage set point and wherein a rate of update of the voltage set point is significantly slower than adjusting the network volt-ampere reactive by controlling the switch to enable the VAR compensation component based on the determination.
14. The system of claim 11 , wherein the at least two of the plurality of shunt-connected, switch-controlled VAR sources receive different voltage set points.
15. The system of claim 1 , wherein the processor is further configured to detect an overvoltage condition and disable the switch based on the detected overvoltage condition.
16. The system of claim 1 , wherein the system self-determines which VAR compensation components of the VAR source are enabled and which VAR compensation components of the VAR source are not enabled.