The core advantage of replacing braking resistors with elevator energy feedback devices is to convert wasted electrical energy into reusable resources, while optimizing system performance and reducing long-term costs. The following is a specific analysis:
1、 Efficient energy recovery and utilization
1. Energy conservation and consumption reduction
The elevator energy feedback device converts the regenerated electrical energy generated by the elevator's power generation state (such as heavy load down or light load up) into AC power of the same frequency and phase as the power grid through power electronics technology (such as IGBT inverter), and directly feeds it back to the power grid or other equipment in the building (such as lighting and ventilation systems) for use, with a power saving rate of up to 15% -45%; The braking resistor converts electrical energy into thermal energy through resistance, resulting in complete energy waste.
Typical benefits: A single elevator can save about 3000-6000 kWh of electricity annually, and after nationwide promotion, the annual energy savings are equivalent to the power generation of a Xiaolangdi hydropower station (about 5.2 billion kWh).
2. Economic improvement
Lower long-term costs: Although the initial investment of the elevator energy feedback device is relatively high (about 3-5 times that of the braking resistor), it can significantly reduce operating electricity costs due to energy recovery, and the cost can generally be recovered within 2-3 years; Although the initial cost of braking resistors is low, they require regular replacement and have higher long-term power consumption costs.
Reduced maintenance costs: Heating of brake resistors can easily lead to aging and require frequent maintenance; The elevator energy feedback device is basically maintenance free.
2、 System performance optimization
1. Reduce equipment load
When the braking resistor works, it generates high temperature, which will push up the temperature of the elevator machine room (requiring additional air conditioning cooling) and accelerate the aging of components such as the frequency converter and control board during long-term operation; The elevator energy feedback device eliminates heat sources, reducing the temperature of the machine room by 5-10 ℃ and extending the equipment life by more than 30%.
2. Enhance operational stability
The elevator energy feedback device quickly eliminates pump voltage (hysteresis voltage control technology), avoids circuit fluctuations caused by braking resistors, improves elevator braking efficiency and ride comfort, and reduces crashes caused by overheating.
3、 Environmental Protection and Compliance
1. Reduce carbon emissions
Recycling electricity directly reduces the total energy consumption of buildings and helps achieve the "dual carbon" goal. For example, a single elevator can reduce its annual carbon dioxide emissions by about 3-6 tons.
2. Compliant with green building standards
Meet energy-saving requirements such as LEED certification, respond to energy-saving regulations for special equipment, and enhance the corporate social responsibility image.
4、 Comparison of Technical Applicability
Advantages of scene elevator energy feedback device and limitations of braking resistance
High rise/high-frequency elevators have significant energy-saving effects (such as shopping malls and hospitals), with a high risk of resistance overheating and soaring energy consumption costs
The grid conditions require stable grid support, and the harmonic suppression technology is mature (THD<5%) without grid requirements, but the energy utilization rate is zero
Initial budget is suitable for long-term investment and only suitable for limited budget or low-frequency usage scenarios
summary
The core value of elevator energy feedback devices is to achieve energy-saving benefits (up to 45%), system reliability improvement (cooling and fault reduction), and environmental compliance through energy recycling, especially suitable for elevator scenarios with medium to high frequency use. And the braking resistor is only used as a low-cost backup solution, suitable for power grid restrictions or temporary renovation needs.