Regenerative effect in Elevators and benefits

Benefits of Regenerative Drives in Elevators and offering suitable Inverters for utilizing regenerative energy.

1. Regenerative Type Load- Lift & Elevator applications. ProstarM Energy Offering 3 Phase Power Solutions

2. Regenerative Loads - Introduction Regenerative Loads can be found in many applications like : Lift & Elevators, etc. “ Regenerative load” is a load that returns active power back to the Source, instead of burning it. Lifts / Elevators

3. Regenerative Loads - Introduction Major Brands with larger market share. Regenerative power can be a benefit when used effectively for energy saving and efficiency .

4. Regenerative Loads - Introduction Principle When the counterweight is heavier than the car, the elevator motor regenerates energy as car moves up . The same principle applies when the car is heavier than the counterweight and moving down . This energy can be captured and used to power other loads in the building.

5. Regenerative Loads - Elevators We can define 2 modes of operation for an elevator : Forward Mode : When the Elevator is moving upwards with a fully populated car, the motor drive is in forward mode (normal mode), drawing energy from Mains or UPS. The motor converts the supplied electrical energy into kinetic energy Braking Mode : Elevator motors operate like a generator while braking (when moving down with a fully populated car, or moving upwards with an empty cabin) Regenerative Power can be seen as an advantage of energy saving. During braking, the motor restores part of the kinetic energy. Some elevators will use a braking resistor to sink this energy. New generation of elevators include IGBT module capable to transform kinetic energy into electrical power and return it to the Grid.

6. Regenerative Loads – UPS/ DG Set – Problems? •However, it can be a problem for generators and OnLine -UPS’s that supply such loads. The regenerative power shouldn't exceed the power used by other connected loads PkW regenerative ≤ PkW connected loads Some UPS companies will give a DBR ( Dynamic Breaking Resistor) box to BURN this POWER Negating the Advantage of Regen Power

7. Power Flow - Regenerative Load with UPS « BRAKING MODE » Regenerative load : When the battery gets energy back (like during braking ), the DC power system can't store or release that energy. This makes the DC voltage to rise steeply , reaching the high limit. When this happens, the UPS stops the inverter and moves the load to the bypass source . BRAKING MODE DC power system can't store or release DC-DC Converter

8. Regenerative Loads – Smart Inverter– Solutions ! •Regenerative Power can be consumed by other loads + Can be fed to GRID Adding other loads in parallel helps mitigate the global regenerative Power returned to the INVERTER and optimize the power consumption. PkW regenerative ≤ / >_ PkW connected loads

9. Power Flow with Smart Inverter- Regenerative Load in « FORWARD MODE with Mains » FORWARD MODE INVERTER

10. Power Flow with Smart Inverter- Regenerative Load in « BRAKING MODE with Mains » BREAKING MODE INVERTER

11. Power Flow - Regenerative Load in « BRAKING MODE without Mains » BRAKING MODE INVERTER