Application of full four-quadrant AC power supply in testing AC motors
"Alternating current motor" is a machine used to convert mechanical energy and alternating current energy into each other. Compared with DC motors, AC motors have a simpler structure without a commutator, are more convenient to manufacture, and are relatively firm. It is easy to make a high-speed, high-voltage, high-current, and large-capacity motor. The convenient AC power supply also makes the AC motor the most widely used type of motor.
*Figure 1 Schematic diagram of AC motor*
In actual use, the motor often works together with various drives, frequency converters and other control components, which can more accurately simulate the various working states of the motor and help to better test the performance of the motor control system. A motor user of ITECH put forward new requirements for motor simulation.
ITECH application example
Testing requirements:
A customer requested to simulate a 150kVA AC motor, not only to simulate the AC motor as a load to absorb electric energy, but also to simulate the reverse electromotive force output by the AC motor when the motor is locked. The specific requirement is to realize the conversion of continuous positive and negative power output.
Test Methods:
If it is a solution built with an ordinary AC power supply and an AC load on the market, the AC load absorbs the power supply, and then switches to the AC power supply to provide the reverse electromotive force, then seamless switching between positive and negative power cannot be achieved, and the control is extremely cumbersome.
IT7900P high-performance grid simulator has the characteristic of integrating source and load, and is a full four-quadrant AC power supply. The list function in IT7900P load mode can realize the switching of positive and negative power by changing the phase angle difference between voltage and current in each working step. Users are very satisfied with the real measured results.
*Figure 2 IT7900P Positive and Negative Power
Switching Waveform Measured*
*Figure 3 IT7900P list phase difference setting interface*
Adopting advanced SiC technology, the IT7900P series high-performance Regenerative grid simulator provides an all-in-one test solution that can be used not only as a grid simulator and four-quadrant power amplifier, but also as a four-quadrant regenerative AC/DC electronic load. The full four-quadrant operation, regenerative ability can feedback power to the grid, meet the needs of environmental protection, but also save a lot of electricity and heat dissipation costs. Compact, modular and efficient structure design allows the IT7900P up to 15kVA in 3U single unit, and its power can be extended to 960kVA after master-slave parallel connection. Colorful touch screen with intuitive GUI allows IT7900P to directly define different waveforms. The rich operation modes can meet the test requirement of single-phase, three-phase, reverse-phase and multi-channel. It provides high flexibility for testing and can be widely used in many fields such as PV, ESS and EV.
