Energy Storage PCS

Energy storage systems are a crucial component of modern renewable energy systems. They are widely utilized as they effectively reduce energy waste and improve the overall efficiency of power systems. Due to the interaction between batteries and the power grid, converters are required to perform AC-DC conversion and enable bidirectional energy flow. Additionally, converters play a vital role in energy storage systems by regulating power through controlling the magnitude and direction of current, enabling peak shaving and valley filling to enhance energy utilization efficiency, as well as providing overload protection to ensure system safety.

Between the rectifier circuit and the converter circuit, a DC-LINK capacitor is required for current support and filtering. Its primary function is to absorb the high pulse current at the DC-LINK bus, preventing high pulse voltage from being generated on the impedance of the DC-LINK. This also protects the load end from the impact of overvoltage.

YMIN capacitors have the following characteristics in the converter field

1. High Capacity
   The DC-Link capacitor stores electrical energy, enabling it to supply continuous power to the converter system during significant grid voltage fluctuations or power outages, ensuring the normal operation of the system. Additionally, when the converter system requires a large amount of energy, the DC-Link capacitor can rapidly release stored energy to meet transient demands. In inductive loads such as motors, the capacitor also provides reactive power compensation, stabilizes voltage, and improves motor performance. This plays a crucial role in enhancing system efficiency and stability.

2. Ultra-High Voltage Resistance
   YMIN capacitors, with their ultra-high voltage resistance, can also serve as protective components. During converter operation, they safeguard sensitive electronic components from damage caused by voltage spikes. This enables energy storage converters to provide stable voltage and frequency support to the power grid, ensuring the reliable operation of the system.

3. High Current Surge Resistance
   YMIN capacitors effectively absorb high pulse currents generated by the converter at the DC-Link end, enabling precise output power regulation through current control. This ensures the converter meets the demands of various scenarios and delivers high-quality AC output. During the soft-start process of converters, YMIN capacitors form part of the charging circuit, helping to prevent excessive impact on the input power supply and load.

4. Long Life
   YMIN capacitors, manufactured through standardized processes and subjected to rigorous pre-delivery testing, feature high density and excellent current surge resistance. These qualities enable converters in energy storage systems to operate stably over extended periods, reducing failures and maintenance costs.

Snap-in aluminum electrolytic capacitor selection recommendation

The role, advantages and characteristics of snap-in aluminum electrolytic capacitors in converter PCS applications:
High voltage resistance: High voltage capacitors can handle larger currents and withstand shocks caused by instantaneous high voltage or load fluctuations.
Low equivalent series resistance (ESR) and high ripple current tolerance: With low ESR and high ripple current resistance, the low ESR of the capacitor helps reduce voltage fluctuations and improve system stability.
Long life and high reliability: High temperature resistance and long life ensure its stable operation in harsh environments. This is essential for long-term uninterrupted energy storage applications such as wind power and photovoltaic power generation.
Good thermal management characteristics: Effectively dissipate heat to prevent overheating from causing performance degradation or failure.
Volume optimization: High capacity density while taking up less space.

Recommended film capacitor selection

The role, advantages and characteristics of film capacitors in converter PCS applications:
Lower series resistance (ESR): Compared with traditional electrolytic capacitors, it has lower ESR, smaller losses, and improves the efficiency of the entire system.
High voltage resistance: It can withstand higher voltages to ensure the stable operation of the system under high voltage environments. Its rated voltage range can reach 350V-2700V, meeting the needs of different application scenarios.
Excellent temperature stability: Higher temperature stability, through high-quality materials and advanced manufacturing processes, ensures stable performance in high temperature environments.
Longer service life: Metallized film capacitors have a longer service life and provide more reliable support for power electronic systems.
Smaller size: Innovative advanced manufacturing process technology not only improves the capacitance density of capacitors, but also greatly reduces the volume and weight of the entire machine with a smaller volume, providing more possibilities for the portability and flexibility of the equipment.
Higher cost performance: DC-Link film capacitor series products have 30% higher dv/dt tolerance and 30% longer life than other film capacitors on the market, which not only provide better reliability for SiC/IGBT circuits, but also provide better cost-effectiveness.

Summarize

YMIN capacitors play a vital role in energy storage systems by virtue of their large capacity, ultra-high withstand voltage, and long life. They help energy storage inverters complete bidirectional power conversion, power regulation and other functions, and optimize the load distribution of the power grid by means of peak shaving and valley filling. They improve the energy utilization efficiency of the inverter in the energy storage system and are the best choice for inverters in the capacitor field.

Original Article Link: https://www.ymin.cn/news/injecting-new-vitality-into-energy-storage-converters-and-leading-the-energy-efficiency-revolution-application-of-ymin-capacitors/