AC Bus Black Start Timing for Parallel Power Supply Units
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing black start methods for power systems either rely heavily on high-speed communication lines or require large device capacities, leading to increased hardware costs and prolonged black start durations.
Innovation Solution
A power system design where alternating current power supply units are divided into primary and secondary units, with the secondary units connecting to the bus when the bus voltage is in a rise phase, allowing them to output voltage in an open-circuit state, thereby reducing hardware requirements and shortening the black start time without increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If synchronous black start manner is used where multiple black-start power supplies are connected in parallel before startup, then the power system can achieve coordinated voltage output, but the reliability heavily depends on high-speed communication lines and the system complexity increases
Solution Approach 1:
The patent segments the power supply units into primary and secondary units based on their connection timing to the bus. Primary units connect before startup while secondary units connect during the voltage rise phase, allowing asynchronous operation without requiring complex communication coordination between all units.
Solution Approach 2:
The primary power supply units perform preliminary action by connecting to the bus before startup and establishing the initial voltage. This preliminary voltage establishment enables secondary units to subsequently connect during the voltage rise phase without requiring complex synchronization communication.
2Device complexity
If asynchronous black start manner with one power supply establishing voltage first is used, then communication complexity is reduced, but the first connected power supply requires large device capacity to independently bear black start load, increasing hardware costs
Solution Approach 1:
The patent segments the power supply units into primary and secondary units based on their connection timing to the bus. Primary units connect before startup while secondary units connect during the voltage rise phase, allowing asynchronous operation without requiring complex communication coordination between all units.
Solution Approach 2:
The primary power supply units perform preliminary action by connecting to the bus before startup and establishing the initial voltage. This preliminary voltage establishment enables secondary units to subsequently connect during the voltage rise phase without requiring complex synchronization communication.
3Device complexity
If asynchronous black start with platform period is used where voltage remains unchanged, then power supply units can be connected sequentially, but the black start duration is increased
Solution Approach 1:
The primary power supply units perform preliminary action by connecting to the bus before startup and establishing the initial voltage. This preliminary voltage establishment enables secondary units to subsequently connect during the voltage rise phase without requiring complex synchronization communication.
Solution Approach 2:
The patent employs dynamic voltage rise control where the bus voltage continuously rises from zero to rated voltage without maintaining a platform period. Secondary power supply units are dynamically connected during this voltage rise phase, allowing continuous progression and reducing the overall black start duration compared to static platform-based methods.
4Ease of operation
If a single power supply unit is used to establish voltage, then the system is simple to operate, but the start speed is limited by the single unit's capacity
Solution Approach 1:
The patent segments the power supply units into primary and secondary units based on their connection timing to the bus. Primary units connect before startup while secondary units connect during the voltage rise phase, allowing asynchronous operation without requiring complex communication coordination between all units.
Solution Approach 2:
The patent merges the capabilities of multiple power supply units by allowing them to connect at different times (primary units before startup, secondary units during voltage rise) and work together to establish the system voltage. This combining of multiple units' capacities accelerates the black start process while maintaining operational simplicity through asynchronous connection.
Data Source
AI summary
A power system and a method for starting a power system. The power system includes a first alternating current bus, a plurality of alternating current power supply units, a plurality of switch units, and at least one controller. The controller is configured to: start a primary alternating current power supply unit to output an alternating current voltage to the first alternating current bus, control a secondary alternating current power supply unit to output an alternating current voltage in an open-circuit state, and control the secondary alternating current power supply unit to output a voltage to the first alternating current bus when a bus voltage value is greater than or equal to a second threshold and is still in a rise phase.