How to use a three phase induction motor as a generato

Three-phase induction motors are plentiful and relatively inexpensive new or used, due to their widespread application throughout the industry. There are several methods of using them as generators, which vary greatly in complexity and convenience to do it yourself. The best practical approach is to connect it as if it were a normal motor application, and then overload it while the motor is operational: with a motor, windmill, or turbine to reverse the current flow and push the power back to the grid. . This practice effectively slows down the demand meter.

motors image by Dusan Radivojevic from Fotolia.com

Note the information on the 3-phase induction motor nameplate including voltage, power rating, and rpm (revolutions per minute). This information will help you correctly match the motor to an external motor or power supply that will allow the motor to function as a generator.

Connects L1, L2 and L3 (and ground terminal leads) of the motor to the three 208 volts, three phase power leads and ground, just as if it were a motor application. It uses a three-phase hard contact motor switch in addition to the main switch that will allow you to disconnect the motor from mains power if necessary.

Divide the normal speed of the gasoline engine in rpm by the rpm of the indicated engine. Most gasoline engines (power equipment type) run at 3600 rpm. If the induction motor rotates at 3600 rpm, the ratio is 1: 1, in order to use the same diameter pulleys in both the gasoline and three-phase engines to transmit the driving force to the engine. This will allow the gasoline engine to only slightly saturate the engine to produce electricity. If the 3-phase motor is rated at 1800 rpm, it should be reduced to half the size of the pulley on the motor so that it can drive the slowest motor within its 1800 rpm range.

Mount the motor in line with the motor on a solid base in the correct direction so that they rotate together according to the required motor rotation direction. A compromise idler pulley will also be installed to allow engine and machine to be decoupled for start-up purposes.

Start the gasoline engine. Start the three-phase induction motor with its starter switch. After warming up, set the gasoline engine to full speed, where its governor will be 3600 rpm. Engage the transmission belt with the lever of the participation bone belt. Slightly increase the gasoline engine to about 3650 rpm, at which point the engine produces electricity rather than consuming it. This will make the demand power meter facilitate speed reduction as the three phase power actually flows to other power motor users in the facility. The power company views this situation as if it were operating less equipment in the facility.

An extra feature of the induction motor in this application is that it intrinsically stays precisely in phase with the power company’s 60 cycles per second cadence set.

Tips

It uses the three-phase induction motor in overdrive mode with speed-controlled mills or water turbines to generate additional power as available.

Warnings

The independent alternative method of generating alternating current with three-phase induction motors requires running them outside of their intended design and safe development, and making considerable modifications to their approved circuit diagram for use as motors. They should be performed only by highly qualified professionals at your own risk.

The energy produced by these motors when used as independent generators can cause serious injury or death at the hands of unqualified professionals.

 

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