Utility-scale renewable peaker plant, tightly coupled solar PV and energy storage
An exemplary power system includes a DC power bus and a photovoltaic system connected to the DC power bus. An energy storage system is connected to the DC power bus and stores energy injected to the DC power bus by the photovoltaic system. A power inverter is connected to the DC power bus and converts power between the DC power bus and an AC connected load. The power system also includes a control system that receives power system data from one or more sub-systems and devices connected to the DC power bus, and controls, in real-time, one or more of the power inverter and the energy storage system to act as a load on the DC power bus based on the received power system data.
1. A control system for a power system having a renewable energy source and an energy storage system, the control system comprising:
a control circuit configured to receive power system data from one or more sub-systems and devices of the power system connected to a DC power bus; and control, in real-time, one or more of a power inverter and the energy storage system of the power system to act as a load on the DC power bus based on the received power system data; and
one or more sensors connected to the DC power bus, an AC connected load, or both;
wherein the control system is configured to, in real-time, increase or decrease real power injected to the AC connected load in response to a change in frequency on the AC connected load based on measured parameters from the one or more sensors or the power system data.
2. The control system according to claim 1 , wherein:
the one or more sensors are configured to measure parameters of the one or more sub-systems and devices of the power system, parameters of the DC power bus, or parameters of the AC connected load.
3. The control system according to claim 1 , wherein the control circuit includes one or more of a first control circuit of the control circuit, a second control circuit of the renewable energy system, a third control circuit of the energy storage system, and a fourth control circuit of the power inverter.
4. The control system according to claim 1 , wherein:
the control system comprises one or more processors; and
the one or more sensors are connected to the DC power bus; and
the one or more processors are configured to receive the power system data from the one or more sub-systems and devices as an input signal encoded with one or more of status data, condition data, current data, voltage data, dispatch data, power grid data, or weather data.
5. The control system according to claim 4 , wherein the input signal received from a server of a power provider is a dispatch signal that includes dispatch data, and the control system controls the power inverter to act as the load on the DC power bus based on receipt of the dispatch signal from the server of the power provider.
6. The control system according to claim 4 , wherein the one or more processors is configured to generate command signals for controlling at least the power inverter and the energy storage system, the command signals being in the form of real or reactive power.
7. The control system according to claim 1 , wherein the one or more sub-systems and devices includes at least one of: the one or more sensors connected to the DC power bus, the renewable energy source, the power inverter, one or more weather stations, or a server of a power provider.
8. The control system according to claim 1 , wherein the power inverter includes a bi-directional power inverter.
9. The control system according to claim 1 , wherein, if current injected on the DC power bus by the renewable energy source is less than the input setpoint of the AC connected load, the energy storage system discharges stored current onto the DC power bus to supplement the current injected on the DC power bus by the renewable energy source and, and the power inverter is controlled, in real-time, to act as the load.
10. The control system according to claim 1 , wherein if a power dispatch signal is received from a server of a power provider, the control system controls the power inverter to act as the load on the DC power bus.
11. The control system according to claim 10 , wherein:
control circuits of the energy storage system and the renewable energy source are configured to receive input signals from the one or sensors connected to the DC power bus and command signals from the control system; analyze the received input, command signals, or both; and control an operating mode of the renewable energy source and the energy storage system, respectively, based on the analysis.
12. The control system according to claim 11 , wherein the input signals include voltage data and current data, and the command signals include control data.
13. The control system according to claim 1 , wherein if data received from the power inverter, the one or more sensors connected to the DC power bus, or both indicates that current injected on the DC power bus by the renewable energy source exceeds an input setpoint of the power inverter, the control system controls, in real-time, both the power inverter and the energy storage system to act as loads on the DC power bus so that current is injected to the AC connected load and excess current is stored in the energy storage system.
14. The control system according to claim 1 , wherein the control system is configured to, in real-time, increase or decrease the real power injected to the AC connected load in response to the change in frequency on the AC connected load by controlling the power inverter to act as the load on the DC power bus based on the change in frequency measured from the AC connected load via the one or more sensors.
15. The control system according to claim 1 , wherein the control system is configured to, in real-time, increase or decrease reactive power injected to the AC connected load in response to a change in voltage on the AC connected load by controlling the power inverter to act as the load on the DC power bus.
16. The system according to claim 1 , comprising:
a first bi-directional converter coupled to the renewable energy source; and
a second converter coupled to the energy storage system;
wherein the first bi-directional converter and the second converter have a common voltage for the DC power bus.
17. The control system according to claim 1 , wherein the control system is configured to, in real-time, increase or decrease reactive power injected to the AC connected load in response to a change in voltage on the AC connected load.
18. The control system according to claim 1 , wherein the control system is configured to, in real-time, increase or decrease the real power injected to the AC connected load based on a state of the energy storage system by controlling current setpoints of the power inverter and energy storage system.
19. The control system according to claim 1 , wherein the control system is configured to balance a state of charge of one or more energy storage systems in an energy storage facility.
20. The control system according to claim 1 , wherein the control system is configured to, in real-time, restrict a rate of increase or decrease in power injected to the AC connected load.