Elevator Energy-saving Metering Solution

1. Elevator Regenerative Energy Generation Conditions

Elevators are typical potential energy loads. Under three operating conditions, the traction motor will deviate from its power-consuming mode and reverse to become a generator, producing regenerative energy.

Heavy-load descent: The car's load is greater than the counterweight's weight. The car moves downwards under its own weight, passively driving the traction motor to rotate and generate electricity; Light-load/empty-load descent: The counterweight's weight is greater than the car's weight. The counterweight falls, pulling the car upwards, and driving the motor in the reverse direction to generate electricity; Deceleration and braking phase: As the elevator approaches the target floor and decelerates until it stops, the large amount of mechanical kinetic energy accumulated during operation is released and converted into electrical energy. After installing an energy feedback device, the average overall energy saving rate of elevators can reach 30%, and the energy saving rate exceeds 40% in high-frequency usage scenarios. For elevator-dense buildings such as high-rise office buildings, commercial complexes, and large residential communities, it has significant energy-saving and cost-reduction value.

2. On-site measurement instruments need to be installed on both the AC grid-connected side and the DC bus side to simultaneously complete power generation statistics, conversion efficiency verification, and power quality monitoring. The instrument selection schemes for the two types of measuring points are as follows: (I) AC grid-connected side meter: Statistically measure the overall power consumption and feedback power of the elevator. Installation point: 380V three-phase incoming line of the elevator distribution cabinet or grid connection terminal of the feedback device. Core function: Measuring the total power consumption taken by the elevator from the grid and the regenerated power fed back to the grid, calculating the energy-saving benefits of the whole elevator. There are two engineering schemes: Wired networking scheme (standard configuration for new buildings/batch renovation) Select DTSD1352 three-phase rail-mounted energy meter, which supports three-phase four-wire wiring, 0.5S class four-quadrant bidirectional metering, and can be matched with open-type current transformers, suitable for batch elevator unified wiring renovation in communities and commercial buildings.

For wireless IoT solutions (in older buildings and scenarios with difficult wiring), the ADW300 series IoT meters are selected. Equipped with a 4G/WiFi communication module, they support TCP data pass-through and directly upload collected data to the cloud platform. This makes them suitable for detached buildings and the retrofitting of dispersed elevators in older residential communities. The meters can collect real-time power quality parameters across all dimensions, including three-phase voltage, three-phase current, bidirectional active/reactive energy, apparent power, power factor, total harmonic distortion (THDi), harmonic content, and DC component.

DC Bus Side Meter: Accurately measures DC regenerative power generation. Installation location: Inside the energy feedback device (DC540V/750V DC bus). Core function: Independently calculates the conversion efficiency of the feedback device itself; when used with supercapacitors or lithium battery energy storage systems, accurately measures the charging and discharging data of regenerative DC power. Recommended model: DJSF1352-RN Bidirectional DC Rail Meter. Product advantages: Measurement voltage coverage DC0~1000V; compatible with 75mV shunt, 0~20mA/0~5V/0~10V Hall sensor; supports dual-channel DC synchronous acquisition, can simultaneously calculate regenerative power generation and energy storage charging and discharging, and the metering accuracy can be selected as 0.5 class/1 class.

For wired meters, a data acquisition gateway is required to upload data to the cloud. Two DIN rail-mounted data acquisition terminals are recommended: ANet-1E2SM-4G and AWT100-4G. The devices collect meter data downlink via an RS485 interface and Modbus-RTU standard protocol, and uplink supports multiple transmission methods including 4G, WiFi, and Ethernet. The appropriate terminal can be selected based on the requirements of the backend management platform.

References

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