Power Control Apparatus for Generator Overcurrent Protection
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Solution Overview
Problem
Conventional electric power systems lack real-time control mechanisms to prevent separation from the power grid during accidents, particularly due to uncontrolled overcurrent and overvoltage issues during low voltage conditions, and they do not have devices to continuously operate under such conditions.
Innovation Solution
A power control apparatus using a resistance device to detect and control overcurrents and overvoltages by comparing measured currents and voltages with rated values, and employing a controlling unit to drive switches and consume error currents through resistance components, ensuring stable power generation and grid connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional DC-DC converter is used inside power converter, then power can be controlled by limiting direct current, but the system cannot detect real-time current changes to prevent generator separation during accidents
Solution Approach 1:
The patent introduces a separate power control apparatus as an intermediary device between the converter and inverter. This apparatus includes a current detector that monitors current in real-time and a controller that adjusts the duty cycle of switching elements to control power flow. This intermediary structure enables real-time current detection and active power control without modifying the core DC-DC converter functionality, thereby improving reliability during accidents while maintaining manageable device complexity.
2Quantity of substance
If electrolytic capacitor is used for DC capacitor, then large capacity is achieved at low cost, but the capacitor produces heat reducing capacitance and shortening lifetime
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors the current flowing through the electrolytic capacitor and adjusts the duty cycle of the switching elements accordingly. When the capacitor approaches its current limit or temperature rises, the controller reduces the duty cycle to limit current flow, preventing overheating and capacitance degradation. This feedback control extends the capacitor's operational lifetime while maintaining its large capacity advantage.
3Reliability
If power control apparatus is not equipped with real-time detection device, then system structure is simpler, but the system cannot prevent separation from power grid during low voltage accidents
Solution Approach 1:
The patent incorporates a current detector and controller that continuously monitor system conditions before critical failures occur. The controller is pre-programmed with thresholds for safe operating conditions and proactively adjusts the duty cycle when approaching these thresholds. This preliminary action prevents the system from entering dangerous states that would cause generator separation, ensuring continuous operation during low voltage accidents without requiring complex real-time detection equipment.
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 effectively prevents generator separation from the power grid by managing overcurrents and overvoltages, maintaining reliable power quality and continuous operation even during low voltage conditions, enhancing the stability and efficiency of power generation systems.
Implementation Method 1
a resistance device to detect and control an overcurrent induced above a rated current
Implementation Method 2
a resistance device in a direct current capacitor of a power converting unit, which is connected to the generator, to detect and control an overvoltage induced above a rated voltage
Data Source
AI summary
The present disclosure is related to a power control apparatus and a method for controlling power, more specifically to a power control apparatus that controls the risk of overcurrent in a power generator when the voltage in the power grid is low. In accordance with an embodiment of the present disclosure, a power control apparatus that controls power in a power generation system including a generator generating power can include a current comparator, which calculates an error current by using a difference between a current measured at the generator and a rated current of the generator, a controlling unit, which calculates a real power value by receiving the error current and outputs a switch driving signal corresponding to the calculated real power value, a switch, which is operated by the switch driving signal, and a resistance device, which is coupled to the switch to consume the error current.