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VECTOR R&D Task FURTHER PEBB-1 CHARACTERIZATION EFFORTS. Presented to: PEBB Technical Review 7-9 April 1998 Robert White VECTOR Research. Background. Previous NSWC PEBB-1 demonstrator testing primarily focused on: DC-AC, 3-phase & single phase (H-bridge) inversion DC to DC buck.
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VECTOR R&D TaskFURTHER PEBB-1 CHARACTERIZATION EFFORTS Presented to: PEBB Technical Review 7-9 April 1998 Robert White VECTOR Research
Background Previous NSWC PEBB-1 demonstrator testing primarily focused on: • DC-AC, 3-phase & single phase (H-bridge) inversion • DC to DC buck
Experimental Goals Conduct tests and measurements designed toImprove our understanding of the operating characteristics of the PEBB design as a function of standard shipboard metrics • Extend and better define the operating range of PEBB-1 modules and demonstrators. • Test concepts of interest that appear in the literature. • Formulate and document direct comparisons between simulation results and measured results
Initial PEBB-1 Checkout • Set-up and operate a PEBB-1 demonstrator in a manner that duplicates previous test conditions • 60- Hz, single phase H-bridge, fixed boost, 5000 Hertz switching frequency, low to moderate power level {120-degree phase difference phase A to C}. • Using the controller and other parts from the PEBB-0 demonstrator. • Demonstrate effectiveness of closed loop tank cooling system and closed loop chilled water cooling unit in controlling PEBB operating temperatures
Phase 1 Experiments • Sustained full 3-phase 60-Hz Operation • Previous 3-phase tests often resulted in failure of phase B for unknown reasons • Determine if new configuration solves this problem • Demonstrate Single-phase operation using only one-phase leg • AC return through the DC midpoint • Single-phase operation using an H-bridge and 180-degrees between phase-legs. • This should result in a higher AC voltage than the 120-degree H-bridge previously used.
Phase 2 Experiments Using variable boost or LMARC: • Full 3-phase 60-Hz Operation • Single-phase using an H-bridge and 120-degrees between phase-legs • Single-phase using an H-bridge and 180-degrees between phase-legs • Single-phase operation using only one-phase leg
Phase 3 Experiments • Determine the maximum range of AC voltage output that can be obtained through software changes for a fixed DC input voltage (300 volts). • Determine the lowest practical DC voltage needed to generate typical Navy shipboard power, 450 volts, 3-phase Delta • determine how power quality degrades with reduced DC bus voltage
Phase 4 Experiments • Determine effects of sudden load changes, both increases and decreases. • Propose/evaluate solutions if necessary • Duplicate and compare measured results to simulated results presented in Simulation of the Auxiliary Resonant Pole Commutated (ARCP) PEBB Inverter by PDI Division of Bird Johnson Company, Report 506051-01 April 1997. • Perform and compare other ARCP simulations and measured data.
Phase 4 Experiments (continued) • Determine the effect of varying parameters that impact on harmonic distortion such as: • load • switching frequency • boost time and technique • Compare measured results to simulation results where possible.
Phase 4 Experiments (continued) • Attempt to demonstrate the following concept: • Power Electronics 2nd edition, by Mohan Underland and Robbins, page 226 suggests that for a three-phase inverter with low values of mf(frequency modulation, switching frequency/output frequency), a synchronized PWM should be used with an mfthat is an odd integer and a multiple of 3. • This would suggest that for an output frequency of 60, a switching frequency of either 4860-Hz or 5220-Hz would be preferable to a switching frequency of 5000 Hz. • Compare results to predictions and evaluate impacts on PEBB design and costs
Long Range Plans • Further characterize PEBB-1 module (phase switch and AC switch) turn-on and turn-off characteristics with the LEM or similar equipment. Determine the delay-time and characteristics between gate-driver input turn-on/off signals and actual switch operation.
Proposed PEBB-1 Experiments • Determine maximum 3-phase 60-Hz (400 Hz, 15 Hz or other frequencies of interest) 450 volt power output possible with: • Optimized LMARC software. • Improved PEBB-1 module cooling using the products from the VECTOR Thermal Studies task or inputs from other organizations. • Demonstrate efficient AC to DC conversion using ARCP.
Additional Proposed PEBB-1 Experiments • Demonstrate efficient 60-Hz to 400-Hz 3-phase frequency changing. • Demonstrate efficient DC-DC boost. • Determine the maximum potential boost ratio possible. • Demonstrate optimum ramp-starting of a typical Navy Air Conditioner or Air Compressor. • Demonstrate ARCP control of a switched reluctance motor.