Power grid operation control system, device, and method

1. A power grid operation control system for a power grid connected to a plurality of renewable energy power generators and a plurality of thermal/hydroelectric power generators, the power grid operation control system comprising:

an automatic dispatching system that controls the thermal/hydroelectric power generators; and

a renewable energy generation control system that controls the renewable energy power generators;

wherein the automatic dispatching system controls the thermal/hydroelectric power generators by generating an automatic frequency control signal for correcting the power supply and demand imbalance of the power grid; and

wherein the renewable energy generation control system determines an available connection capability, which is the power generation capacity of the renewable energy power generators connectable to the power grid and which varies with time, by taking into account a fluctuation of the load, a renewable energy generator fluctuation ratio, and the system capacity providable by the thermal/hydroelectric power generators, issues individual load dispatching instructions to the renewable energy power generators to ensure that the total power generation capacity of the renewable energy power generators does not exceed the available connection capability, and acquires basic information for determining the available connection capability in coordination with the automatic dispatching system.

2. The power grid operation control system according to claim 1 , wherein the renewable energy generation control system stops the renewable energy power generators upon receipt of information about a fault in the power grid from the automatic dispatching system, and when the electrical power supplied from the power grid is insufficient, exercises fixed output discharge control with energy storage batteries provided for the renewable energy power generators.

3. A power grid operation control device for a power grid connected to a plurality of generators based on renewable energy and thermal/hydroelectric power generators whose electrical power generation is controlled when a frequency control signal based on power supply and demand imbalance is received from an automatic dispatching system, each of the generators based on renewable energy being equipped with a controller that controls the electrical power generation thereof, the power grid operation control device comprising:

a renewable energy generation control system that issues a load dispatching instruction to the controller;

wherein the renewable energy generation control system includes

a first unit that determines an available connection capability, which is the power generation capacity of the generators based on the renewable energy connectable to the power grid and which varies with time, by taking into account a fluctuation of the load, a renewable energy generator fluctuation ratio, and the system capacity providable by the thermal/hydroelectric power generators, and

a second unit that, when the total power generation capacity of the generators based on the renewable energy connected to the power grid is not lower than the available connection capability, issues the load dispatching instruction to the generators based on the renewable energy to ensure that the total power generation capacity does not exceed the available connection capability.

4. The power grid operation control device according to claim 3 , wherein basic information for enabling the first unit to determine the available connection capability is acquired as time zone specific information about a daily operation.

5. The power grid operation control device according to claim 4 , wherein the basic information includes an available control capability, which is an output adjustment range of the thermal/hydroelectric power generators whose output can be changed by the load dispatching instruction based on a frequency control signal, and is acquired as the time zone specific information about a daily operation.

6. The power grid operation control device according to any one of claims 3 to 5 , wherein the utilization factor of each of the generators based on the renewable energy that prevails during a predetermined period is calculated to operate generators other than a generator having a low utilization factor in such a manner that the total power generation capacity does not exceed the available connection capability.

7. A power grid operation control method for a power grid connected to a plurality of generators based on renewable energy and thermal/hydroelectric power generators whose electrical power generation is controlled by a frequency control signal based on power supply and demand imbalance, the power grid operation control method comprising the steps of:

determining an available connection capability, which is the power generation capacity of the generators based on the renewable energy connectable to the power grid and which varies with time, by taking into account a fluctuation of the load, a renewable energy generator fluctuation ratio, and the system capacity providable by the thermal/hydroelectric power generators; and

controlling the generators based on the renewable energy connected to the power grid by determining individual load dispatching instructions for ensuring that the total power generation capacity of the generators based on the renewable energy does not exceed the available connection capability.