Generator Control System Using DC-DC Conversion for ISG
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional integrated starter generator (ISG) systems for portable generators require high-voltage batteries and high-voltage/high-current relays, leading to increased costs, larger system size, and reduced flexibility due to rigid voltage and power generation specifications.
Innovation Solution
A generator control system utilizing a DC port, first and second power conversion circuits, and switch units to boost DC voltage into a bus voltage, eliminating the need for high-voltage batteries and relays, and using transistor switches to reduce system size and cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a three-phase full-bridge conversion circuit is used to start the motor generator, then the engine starting function is achieved, but high-voltage batteries and high-voltage/high-current relays are required, increasing system cost and size
Solution Approach 1:
The patent changes the voltage parameter from high-voltage (48V) to low-voltage (12V) by introducing a DC-DC conversion circuit. This allows the use of low-voltage batteries and low-voltage relays, significantly reducing component specifications, cost, and system size while maintaining the engine starting function through voltage transformation.
Solution Approach 2:
The patent introduces a DC-DC conversion circuit as an intermediary between the low-voltage battery and the three-phase full-bridge conversion circuit. This intermediary transforms the low-voltage DC to high-voltage DC, enabling the motor generator to receive the necessary starting voltage without requiring high-voltage batteries or relays.
2Speed
If high-voltage batteries are used to meet ignition speed requirements, then the engine starting performance is improved, but the battery cost and system size increase
Solution Approach 1:
The patent transforms the voltage parameter using a DC-DC conversion circuit, allowing the use of lightweight low-voltage batteries instead of heavy high-voltage batteries. The conversion circuit boosts the voltage to meet ignition speed requirements, decoupling the battery weight from the required ignition performance.
3Reliability
If relays with higher rating specifications are used for isolation, then the charging safety is improved, but the relay size and cost increase
Solution Approach 1:
The patent changes the voltage level from high-voltage to low-voltage throughout the system, allowing the use of small, low-cost low-voltage relays for isolation and charging control. The DC-DC conversion circuit enables these low-voltage relays to provide adequate protection without requiring large high-voltage relay specifications.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution allows for the use of lower-cost, smaller low-voltage batteries and reduces system size by replacing relays with transistor switches, while maintaining efficient engine starting and power generation capabilities.
Implementation Method 1
a first power conversion circuit (16), wherein a first side of the first power conversion circuit (16) is coupled to the DC bus (14) and a second side of the first power conversion circuit (16) is coupled to the first switch unit (20)
Implementation Method 2
a second power conversion circuit (18), wherein a first side of the second power conversion circuit (18) is coupled to the DC bus (14) and a second side of the second power conversion circuit (18) is coupled to the motor generator (200)
Data Source
AI summary
A generator control system is coupled to a motor generator. The system includes a DC port, a first switch unit, a DC bus, a first power conversion circuit, a second power conversion circuit, and a second switch unit. The first power conversion circuit has a first side coupled to the DC bus and a second side coupled to the first switch unit. The second power conversion circuit has a first side coupled to the DC bus and a second side coupled to the motor generator. One end of the second switch unit is coupled to the first power conversion circuit and the first switch unit, and the other end of the second switch unit is coupled to the DC port.