Research On Coupling Noise Of High-voltage Actuator Of Electrostatic Accelerometer To The Capacitive Transducer

With the high resolution and the ability to monitor six degrees of freedom at the same time,the electrostatic accelerometer is wildly used in space missions,such as measuring the non-conservative forces applied on the spacecraft or serving the drag-free control to observe the earth gravity field.It's necessary to carry out the high-voltage suspension experiment to verify the performance and the resolution of the accelerometer on the ground.The accelerometer experiment with 70g Test Mass?TM?completed by our group has reached the level of 4?10^-8m/s²/Hz^1/2 and found it limited by the ground vibration and high-voltage coupling noise.In order to reduce the coupling noise caused by high voltage,the actuator of the accelerometer and its coupling part has to be surveyed.The thesis theoretically models the high-voltage actuator circuit first and analyzes the influence of component noise on the output.The resistance fluctuation noise and its measurement method are proposed.Then the power supply suppression effect of the high voltage amplifier circuit is studied.Finally,the theoretical calculation of the influence of high-voltage feedback noise on the accelerometer is carried out where the low-frequency noise directly couples to the corresponding electrodes,and the high-frequency noise couples to the output of the sensing circuit through the transformer.By theoretical modeling and experimental testing,the low-frequency noise of the high-voltage actuator is degraded by 5 times,which reduces the coupling noise of the feedback high-voltage to the plate voltage.The parameter optimization optimizes the coupling noise of the high-voltage actuator circuit to 4 times,and found that the secondary resonance is better than the primary resonance so that the noise eventually reaches the level of1.2?10^-6V/Hz^1/2,close to the noise floor of the sensing circuit.Finally,a simulation model of high-pressure levitation accelerometer is established in Matlab/Simulink.The noise curve is fitted according to the measured noise data and brought into the simulation model and the simulation results are consistent with the theoretical calculation.It is concluded that the high-voltage levitation accelerometer is more affected by the actuator-to-sensing coupling noise in the vertical direction and concludes that the high-voltage coupling noise limit in the horizontal direction is 3?10^-11m/s²/Hz^1/2,and reduces the two-level estimation of the high-voltage coupled noise.