2020
Jun.

51

SPECIAL REPORT

Delta builds Taipower's energy storage system
To facilitate energy transition and grids

Text by: EISBG/CPBG/BABG

Delta's energy storage solution has been successfully adopted by Taipower's Xiaxing Power Plant in Kinmen (Quemoy), making it the largest energy storage system for an outlying island, and for Taipower. This case was jointly completed by Delta’s SESBU of the EISBG, ESDBD of the CPBG, and BASBU of the BABG, making it an all-new dispatch control tool for power supply that provides a complete integrated one-stop service for Taipower. The system can provide a backup power supply within 200ms when an emergency generator outage occurs, and can undertake the tasks of regulating frequency of the power grid and smoothing renewable energy during daily operations, which further improves power supply stability. 
 
Provides fast and powerful backup power
Since the power system for Kinmen is not connected to the main island Taiwan, there is a problem of frequency fluctuations. The difference in power consumption between winter and summer can reach up to 35MW. In the event of an unplanned diesel generator outage at a power plant where the power cannot be resupplied immediately, a chain reaction of de-synchronization may cause a power outage over a large area. Although Kinmen continues to build wind and solar electric systems and the proportion of renewable power increases, the duck curve effect of the power grid becomes more obvious. Without the flexibility of frequency modulation and power dispatching, the power demand and system reliability may bring tremendous pressure. 

Increase in proportion of renewable energy causes a duck curve effect
 
To stabilize the frequency of the power grid for Kinmen and reduce the impact of fluctuations on the power generation of renewable energy, Taipower decided to implement an energy storage system at the Xiaxing Power Plant in Kinmen. This created instant backup power. In addition, Taipower installed an energy management system at the Tashan Power Plant to monitor the operation of the Xiaxing Power Plant. 
 
One-stop solution, with highly integrated PCS, battery, environmental monitoring and management software
Delta’s energy storage solutions are composed of various devices: a PCS container that consists of two 1MW power conditioning systems (PCS), a 40-foot lithium-ion battery container of a Battery Energy Storage System (BESS) with a total capacity of 1MWh, a Delta energy storage management system (BEMS), and other surrounding step-up transformers. The integration of these components in the energy storage solution is implemented with Delta’s technical capabilities. In addition to meeting the requirements of the power plant for energy storage systems, Delta also provided management units of Taipower with all the hardware and software products required to build the system in a single purchase, reducing the complexity of cumbersome communication and maintenance through a single service window and accelerating progress on the project. 

Delta builds Taipower's largest energy storage system at Taipower's Xiaxing Power Plant in Kinmen
 
The PCS1000 installed in a 20-foot container for the solution is a megawatt bi-directional power conditioning system that is responsible for controlling, converting, and regulating power. It features functions such as automatic adjustment for voltage and frequency, active and reactive power compensation, anti-islanding protection and independent operating mode, and control via a virtual synchronous generator (VSG), so it can effectively control power and process detection and supply power in 200ms, which is far faster and twice the speed required for the project. 
 
Another component that plays an important role in the system is the container-level battery energy storage system, which uses domestically produced high-power P140 lithium batteries to instantaneously provide a high volume of power. The 40-foot container contains 462 battery modules with a total storage capacity exceeding 1,000 watts. Supplemented by a battery management system (BMS) and the FM200 automatic fire protection system, it can provide a multi-level safety protection mechanism to ensure the safe operation of the system through its functions of monitoring, active notification, and remote control. 
 
 
It is worth mentioning that the Delta energy storage system sets the required mode of operation via a web interface, which allows the dual mode to operate simultaneously. For example, the operation of F-P (Frequency-Watt) mode during daily operations regulates the utility frequency of the power grid to prevent excessive frequency variations. At the same time, the system is also in the real-time RoCoF (Rate of Change of Frequency) state of detection. Once an emergency occurs in which the speed of variation or range of frequency fluctuation on the grid exceeds the set threshold, the system will immediately auto-activate the response mechanism for tripping and send the full load of 2MW power to the grid within 200ms, so as to gain some buffer time to eliminate abnormalities. 
The energy storage system assists the generator in an emergency to maintain the overall supply of power
 
For renewable energy, this energy storage system can regulate solar energy by storing excess power or sending power back to the grid so that the balance of power supply on the grid can be maintained. In addition, the energy storage system can also regulate solar power, reduce variation and fluctuations, and allow renewable energy to be stably connected to the grid.

Energy storage system regulates solar power to reduce fluctuations on the grid
 
To ensure durability and fire safety, an automated management and control system was adopted to complement the energy storage systems. The building control solutions developed by the subsidiaries Delta Controls and LOYTEC were installed for this project to uniformly control the ambient air conditioning, lighting, fire protection, and equipment for detection of water accumulation in the containers. The solutions’ real-time control replaced traditional manual operation to ensure that the container is maintained in an optimized environment with constant temperature and humidity. 

The Building automation solution provides a real-time management platform to create the best environmental monitoring
 
A smart street lighting solution is built around the energy storage system to improve convenience utility and energy efficiency through remote control and automatic scheduling functions. In addition, Delta's LED smart streetlights are used for the lamp head, and VIVOTEK’s network cameras are equipped to the poles as well. In addition to daily surveillance recording, it also features an invisible fence function. When an abnormality is found around the system, the managing personnel of the power plant can be notified immediately to handle the problem. Combined with smart lighting and security features, the solution strengthens the overall security around the place. 
 
Stabilizes the power supply of power plants while energy transition is well under way
Operating with either conventional power generation or renewable power generation, the energy storage system can always take the leading role of regulating and safeguarding the power supply at any time, as well as providing rescue in an emergency. Delta is the leading supplier of energy storage systems in Taiwan, and has the capability to provide one-stop services. Its self-developed complete solutions have long been recognized by customers at home and abroad, such as the Kaohsiung Yongan Solar Power Plant and Japan's Ako Energy Park, where Delta's energy storage solution was adopted. 
 
Delta once again won the favor of Taipower and introduced a more advanced energy storage system solution for Kinmen. After raising the system voltage of the discharge test to 11.4kV, it started to undertake the dispatching of the power grid. After taking on various challenges in engineering, control, and testing, Delta and Taipower’s R&D and engineering personnel have completed the system setup together in 2020. For the future, Delta will continue to develop more powerful and faster-responding systems to provide vital help for stabilizing the power supply of power plants and to support the transition and progress of energy systems.