Power Conditioning Unit (PCU)

The output of renewable energy fluctuates. Stable use of this energy requires a good balance between supply and demand. To achieve this, we need the next-generation power system(PCU).

For stable operation of the power transmission network requires that the output fluctuations be restricted to within a certain range of the required power. Because the output of wind power depends on the strength of the wind, fluctuations in the wind strength can result in output outside the allowed range. When a storage battery is installed and the output from the wind power generator is higher than the allowed range, the storage battery is charged by the excess amount. When the output is less than the allowed range, the charged power in the battery is returned to the power transmission network. In this way, output fluctuations are kept within the allowed range.

The following explanation gives a little more technical detail. In power prioritization and control, the generated output is kept to a constant level by using the inertial energy of the generator and rapid-response electric control. In normal wind power generation, because the torque of the generator is controlled to a constant level, changes in the wind speed generate output fluctuations.

However, in wind power generation that uses power prioritization and control, electric control is used to change the generator rpm and keep the output at a constant level. In other words, when the wind speed drops suddenly, electric control is performed to discharge the inertial energy of the generator and reduce the generator rpm, which restricts the drop in the generated output. Conversely, when the wind speed rises suddenly, electric control is performed to absorb the inertial energy and increase the generator rpm. Electric prioritization and control can restrict rapid wind speed fluctuations that occur in about 1 second, and operate in coordination with turbine blade pitch control (a method of controlling the wind turbine rpm by changing the blade angle). This enables effective control of output fluctuations.

In addition, for large fluctuations that have a long cycle, even greater stability of the power output can be achieved by using the technology described above in combination with technology that restricts output fluctuations by charging or discharging storage batteries.

To achieves a stable power supply by using PCU to prevent the voltage drops that are a concern when connecting wind power generators to a power transmission and distribution networks.

Power Conditioning Unit (PCU) is an integrated system consisting of a charge controller, inverter and a Grid charger.