Dynamical response of the Galileo Galilei on the ground rotor to test the equivalence principle: Theory, simulation, and experiment. II. The rejection of common mode forces

To suppress the direct current (DC) capacitor voltage fluctuations and the common-mode voltage (CMV) in a three-phase, five-level, neutral-point-clamped (NPC)/H-bridge inverter, this paper analyzes the influence of all voltage vectors on the neutral point potential of each phase under different pulse mappings in detail with an explanation of the CMV distribution. Then, based on the traditional space vector pulse width modulation (SVPWM) algorithm, a dual-pulse-mapping algorithm is proposed to suppress the DC capacitor fluctuations and the CMV simultaneously. In the algorithm, the reference voltage synthesis selects the voltage vector that has the smallest CMV value as the priority. In addition, the two kinds of pulse mappings that have opposite effects on the neutral point potential are switched to output. At the same time, regulating factors are introduced to adjust the working time of each voltage vector under the two pulse mappings; then, the capacitor voltages can be balanced. Both the simulation and experiment demonstrate the algorithm’s effectiveness.

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EXPERIMENTAL VALIDATION OF A HIGH ACCURACY TEST OF THE EQUIVALENCE PRINCIPLE WITH THE SMALL SATELLITE “GALILEO GALILEI”

From Quantum to Cosmos ◽

10.1142/9789814261210_0030 ◽

2009 ◽

pp. 387-398

Author(s):

ANNA M. NOBILI ◽

GIAN LUCA COMANDI ◽

SURESH DORAVARI ◽

FRANCESCO MACCARRONE ◽

DONATO BRAMANTI ◽

...

Keyword(s):

Equivalence Principle ◽

Experimental Validation ◽

High Accuracy ◽

Small Satellite ◽

Galileo Galilei ◽

Accuracy Test

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EXPERIMENTAL VALIDATION OF A HIGH ACCURACY TEST OF THE EQUIVALENCE PRINCIPLE WITH THE SMALL SATELLITE "GALILEO GALILEI"

International Journal of Modern Physics D ◽

10.1142/s0218271807011590 ◽

2007 ◽

Vol 16 (12a) ◽

pp. 2259-2270 ◽

Cited By ~ 6

Author(s):

ANNA M. NOBILI ◽

GIAN LUCA COMANDI ◽

SURESH DORAVARI ◽

FRANCESCO MACCARRONE ◽

DONATO BRAMANTI ◽

...

Keyword(s):

Equivalence Principle ◽

Symmetry Axis ◽

High Sensitivity ◽

Momentum Conservation ◽

Small Satellite ◽

Orbit Plane ◽

Galileo Galilei ◽

Long Term Stability ◽

Accuracy Test ◽

Weakly Coupled

The small satellite "Galileo Galilei" (GG) has been designed to test the equivalence principle (EP) to 10-17 with a total mass at launch of 250 kg. The key instrument is a differential accelerometer made up of weakly coupled coaxial, concentric test cylinders rapidly spinning around the symmetry axis and sensitive in the plane perpendicular to it, lying at a small inclination from the orbit plane. The whole spacecraft spins around the same symmetry axis so as to be passively stabilized. The test masses are large (10 kg each, to reduce thermal noise), their coupling is very weak (for high sensitivity to differential effects), and rotation is fast (for high frequency modulation of the signal). A 1 g version of the accelerometer ("Galileo Galilei on the Ground" — GGG) has been built to the full scale — except for coupling, which cannot be as weak as in the absence of weight, and a motor to maintain rotation (not needed in space due to angular momentum conservation). GGG has proved: (i) high Q; (ii) auto-centering and long term stability; (iii) a sensitivity to EP testing which is close to the target sensitivity of the GG experiment provided that the physical properties of the experiment in space are going to be fully exploited.

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An Alternative Carrier-Based Implementation of Space Vector Modulation to Eliminate Common Mode Voltage in a Multilevel Matrix Converter

Electronics ◽

10.3390/electronics8020190 ◽

2019 ◽

Vol 8 (2) ◽

pp. 190 ◽

Cited By ~ 5

Author(s):

Janina Rząsa

Keyword(s):

Output Voltage ◽

Control Method ◽

Matrix Converter ◽

Modulation Method ◽

Space Vector Modulation ◽

Space Vector ◽

Common Mode ◽

Common Mode Voltage ◽

Simulation And Experiment ◽

Vector Modulation

The main aim of the paper is to find a control method for a multilevel matrix converter (MMC) that enables the elimination of common mode voltage (CMV). The method discussed in the paper is based on a selection of converter configurations and the instantaneous output voltages of MMC represented by rotating space vectors. The choice of appropriate configurations is realized by the use of space vector modulation (SVM), with the application of Venturini modulation functions. A multilevel matrix converter, which utilizes a multilevel structure in a traditional matrix converter (MC), can achieve an improved output voltage waveform quality, compared with the output voltage of MC. The carrier-based implementation of SVM is presented in this paper. The carrier-based implementation of SVM avoids any trigonometric and division operations, which could be required in a general space vector approach to the SVM method. With use of the proposed control method, a part of the high-frequency output voltage distortion components is eliminated. The application of the presented modulation method eliminates the CMV in MMC what is presented in the paper. Additionally, the possibility to control the phase shift between the appropriate input and output phase voltages is obtained by the presented control strategy. The results of the simulation and experiment confirm the utility of the proposed modulation method.

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