Voltage Controlled Current Source for Spacecraft Bus Regulation
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Solution Overview
Problem
Previous spacecraft power bus stabilization methods experience large low-frequency ripple and limited amplitude oscillation due to mode transitions, making it difficult to achieve stable voltage regulation, especially when load transients occur.
Innovation Solution
A voltage controlled current source system using a synchronous switch with pulse width modulation (PWM) duty cycle, where the PWM duty cycle is proportional to an error signal based on the comparison of the electrical bus voltage to a reference voltage, stabilizing the bus regulator and improving responsiveness to load transients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If previous spacecraft bus stabilization methods with staggered set-points and mode transitions are used, then the system can operate across a full operating range, but large low frequency ripple and limited amplitude oscillation occur on the bus
Solution Approach 1:
The system segments the power bus regulation into multiple parallel voltage controlled current sources instead of using a single centralized amplifier with mode transitions. Each current source independently regulates a portion of the bus, eliminating the need for staggered set-points and mode switching while maintaining full operating range coverage.
Solution Approach 2:
The voltage controlled current sources are designed to operate continuously across the full operating range without requiring mode transitions. The system prepares for all operating conditions simultaneously through parallel architecture rather than sequentially through mode changes, preventing bus transients and oscillations.
2Adaptability or versatility
If mode transitions are implemented in the central amplifier, then the system can adapt to different operating conditions, but bus impedance becomes very high during transitions
Solution Approach 1:
The centralized amplifier is divided into multiple parallel voltage controlled current sources. This segmentation allows each source to maintain stable bus impedance independently without requiring transitions, as the parallel architecture provides continuous regulation across all operating conditions.
3Stability of the object's composition
If previous stabilization methods are used, then the system can regulate bus voltage, but limited amplitude oscillation persists until solar panel capability increases or load changes
Solution Approach 1:
The parallel voltage controlled current sources are designed to provide immediate response to load transients without waiting for mode transitions or changes in solar panel capability. The system is pre-configured to handle all operating conditions simultaneously, eliminating persistent oscillations.
4Speed
If voltage controlled current source with PWM is used, then the system responds more rapidly to load transients, but the system complexity increases
Solution Approach 1:
The system replaces complex mechanical mode-transition mechanisms with electronic PWM control in voltage controlled current sources. This substitution achieves rapid response to load transients through electronic switching rather than mechanical reconfiguration, reducing overall system complexity despite the use of PWM technology.
Data Source
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AI summary
A system and method for providing a voltage controlled current source for bus regulation is disclosed. A bus current delivered to an electrical bus from a current source is controlled using a synchronous switch according to a PWM duty cycle. Further, the PWM duty cycle is controlled to be proportional to an error signal based on a comparison of a voltage of the electrical bus to a reference voltage.