High-end chemicals

Industry Characteristics:

● High-end chemical processing requires exceptionally high process requirements, making power supply reliability and stability crucial. A slight mishap in the power system could lead to serious safety incidents and significant environmental damage in chemical plants.

● Internal power grids typically consist of three components: transmission, generation, and distribution.

● Distribution reliability requirements are extremely high. For petrochemical plants operating continuously, a power system failure of just a few cycles can cause significant downtime in production facilities, leading to even catastrophic consequences (millisecond-level, resulting in economic losses—unplanned downtime, safety incidents, and environmental pollution).

● Relatively stable loads and balanced three-phase loads. Petrochemical plants typically have relatively stable load profiles, with minimal daily fluctuations. Once production facilities are operating normally, the load remains virtually constant for weeks or even months.

● A certain number of nonlinear loads, such as inverters, UPSs, DC power supplies, rectifier transformers, and thyristor-controlled electric heaters.

● Large Motor Startup: Although large motors such as the main catalytic blower in oil refineries and ethylene polymerization pelletizers rarely start, their long startup times significantly impact bus voltage, posing a critical issue for the power supply and distribution systems of large petrochemical enterprises.

Project Background:

Degraded power quality at a high-end chemical enterprise significantly impacted production safety and efficiency:

1. Power grid flashovers (swings) caused by power line faults and thunderstorms can severely disrupt large areas of petrochemical equipment, causing numerous motor trips and equipment downtime. After the grid voltage recovers, the motors cannot automatically resume operation, requiring manual recovery, which takes a long time. For some unmanned equipment, the recovery time is even longer, disrupting the continuous production process and potentially causing production and equipment failures, seriously threatening plant safety.

2. Transformer losses. Transformer eddy current losses are often approximately nine times higher than expected, almost double the transformer's total load losses. Furthermore, overheating of conductors due to the skin effect adds additional transformer losses. A 20mm diameter conductor in a transformer has an apparent resistance at 3Hz that is higher than the typical DC resistance. This increased resistance in the power system causes an increase in frequency, resulting in voltage drops and drastic voltage fluctuations, which can even lead to a severe decrease in power quality and excessive power loss.

3. False tripping. Chemical plants require large amounts of electricity for production, and this deterioration in power quality can lead to surge currents, which can cause power outages. Surge currents can easily cause circuit breakers to trip. This occurs because the circuit breaker cannot correctly combine the fundamental and harmonic currents in the chemical plant circuits. This often results in false tripping, or even failure to trip when it should, or even the leakage current reaching the set value for the leakage protection device. Therefore, false tripping can cause significant damage to the chemical plant's power system and severely degrade power quality.

4. New power equipment for nonlinear and impactful loads generates a large amount of harmonics while controlling and processing power. This generates a large amount of harmonic current into the grid, severely distorting the voltage waveform at the common connection point. Load fluctuations and impacts lead to various power quality disturbances, such as voltage fluctuations and transient pulses.

Key Customer Focus: The high-end chemical industry is no different from other industries in terms of power quality indicators, except that petrochemical plants have more stringent power supply requirements. The main power quality issues currently faced by high-end chemical companies include:

● Frequency issues – primarily caused by the disconnection of small petrochemical power grids from the larger grid, resulting in isolated operation.

● Voltage issues – divided into voltage swells and sags, known in the industry as "flashovers" or "swings."

● Harmonic issues – Petrochemical companies use a large number of nonlinear loads, such as large-scale power electronics (energy-saving devices and frequency converters), high-power electric drive equipment, DC output devices, chemical rectifiers, and other nonlinear loads.

Solution:

Installing one dedicated unit of Kedelibang New Power at each input of the low-voltage distribution room provides synchronous harmonic control, significantly reducing transformer losses and improving power efficiency. Synchronous reactive power compensation achieves a power factor of 0.99. This stabilizes voltage and current, balances the three phases, avoids nuisance tripping, and completely eliminates power quality issues such as flashovers (swings), truly achieving the dual goals of optimizing power quality and saving energy.

Conclusion:

The chemical plant's power distribution system used two input power sources. With the introduction of Kedelibang's new power equipment, only one input power source was needed, completely resolving grid fluctuations and other issues. Voltage and current distortion were significantly reduced, keeping THDi below 4%. Testing also demonstrated an overall energy saving rate of 10.9%, truly achieving the dual goals of optimizing power quality and energy conservation. Kedelibang's new power equipment provides reliable power quality for high-end chemical continuous production facilities, thoroughly addressing grid interruptions (swings), eliminating harmonic pollution, and achieving energy savings. This results in approximately 1.8 million RMB in annual energy savings.