Machine Tool
INVT GD800 Series Industrial Drives Applied to Motor Test System
Release Time:2015-12-25

Abstract: This paper has introduced the feature of dynamometer in electric motor test system, INVT GD800 series four-quadrant frequency inverter, and it has expounded the scheme and theory of GD800 series inverter applied to dynamometer. Test and the use of the customer's site show that GD800 series inverter has perfect functions, stable performance, and unparalleled advantages on motor test application.


Keywords: low voltage frequency inverter, four-quadrant, GD800, electric motor test, dynamometer


1. Foreword

Electric motor/generator dynamometers are a specialized type of adjustable-speed drive. The absorption/driver unit can be either an alternating current (AC) motor or a direct current (DC) motor. Either an AC motor or a DC motor can operate as a generator that is driven by the unit under test or a motor that drives the unit under test. When equipped with appropriate control units, electric motor/generator dynamometers can be configured as universal dynamometers. The control unit for an AC motor is a variable-frequency drive, while the control unit for a DC motor is a DC drive. In both cases, regenerative control units can transfer power from the unit under test to the electric utility. Where permitted, the operator of the dynamometer can receive payment (or credit) from the utility for the returned power via net metering.

In engine testing, universal dynamometers can not only absorb the power of the engine, but can also drive the engine for measuring friction, pumping losses, and other factors.

Electric motor/generator dynamometers are generally more costly and complex than other types of dynamometers.


Fig.1 Electric dynamometer



2. Brief introduction of GD800

GD800 series industrial drives are developed for sophisticated application market which needs high overload capacity, high reliability and continuous operations. It's designed for various heavy-load applications such as metallurgy, port machinery, shore power, petrochemical, electric power mining, dynamometer etc.

* Specifications: 3AC 400V/500V/690V   4kW-3MW

* Hardware design: Common DC bus, Modular, easy cabinet-built and maintenance

* Technical highlights: high start torque, 150% at 0.3Hz, 200% at 0Hz (Closed loop); Master-slave control; Fieldbus; High reliability optical fiber transfer; Low harmonic

* Application load: two quadrant/ four quadrant, single drives/ multi drives

* Fully test: environment test(temperature, humidity, altitude, vibration), safety test, meets CE requirement


Fig.2 Appearance of GD800


3. System scheme

Like Fig.3 showed, the load motor and under-test motor are connected together on the shaft, use a GD800-26 four quadrant inverter to drive the load motor, we adjust the output frequency and torque of GD800 to change the load on under-test motor, the load motor work as regenerator, the DC bus voltage of inverter increase, then PWM rectifier will transfer the energy back to power grid. In order to improve the torque respond and speed accuracy, closed-loop vector control via encoder is recommended. 


Fig.3 System diagram

5. Site photos




6. Conclusion

Adopt GD800 series inverter in motor test system, realizing motor work in four quadrants, speed and torque control accuracy meets the strict customer requirement, the input side harmonic is less than 2% during regeneration, no harm to the power grid. INVT GD800 four-quadrant drive has good competitive advantage with its excellent performance and service in the motor test system; it has been widely used in Chinese market and some other country.



1. Shenzhen Invt Electric Co., Ltd. <Hardware Manual of Goodrive800 Series Products>• 2012

2. Shenzhen Invt Electric Co., Ltd. <Software Manual of Goodrive800 Series Products>• 2012

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