Photovoltaic System Frequency Stabilization via Virtual Governor Control
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Solution Overview
Problem
Photovoltaic systems face challenges in stabilizing electric power supply due to fluctuations in solar power generation, lacking the frequency adjustment capabilities of synchronous generators, which can lead to instability in system frequency and inefficient operation within varying operating conditions.
Innovation Solution
A photovoltaic system comprising an electric power converter, voltage and current detectors, an effective power detector, system condition detector, and computation units that adjust output voltage and angular frequency to mimic synchronous generator characteristics, ensuring stable power supply by dynamically responding to system conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If photovoltaic power generation is used to provide renewable energy, then greenhouse gas emissions are reduced and environmental sustainability is improved, but the stability of electric power supply deteriorates due to fluctuations in power generation amount
Solution Approach 1:
The patent applies the copying principle by replicating the frequency adjustment characteristics of synchronous generators in photovoltaic systems through control algorithms. The system copies the governor function of synchronous generators by calculating and adjusting power output based on system frequency deviations, enabling photovoltaic systems to exhibit similar stabilizing behavior without physical mechanical components.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the power output parameter of photovoltaic systems in response to system frequency variations. The control algorithm modifies the active power injection or absorption based on frequency deviation magnitude and direction, enabling the system to adapt its operational parameters to maintain frequency stability.
2Adaptability or versatility
If synchronous generators are used for power generation, then frequency adjustment function is provided and system frequency stabilization is improved, but the adaptability to varying operating conditions deteriorates due to fixed operating characteristics
Solution Approach 1:
The patent applies the dynamics principle by implementing a control algorithm that continuously adapts the power output of photovoltaic systems based on real-time system frequency measurements. Unlike fixed characteristic synchronous generators, this system dynamically adjusts its operational state to match varying grid conditions, providing both adaptability and frequency stabilization capability.
Solution Approach 2:
The patent implements feedback control by continuously monitoring system frequency and using this information to adjust photovoltaic power output. The control algorithm receives frequency deviation signals and generates corresponding power adjustment commands, creating a closed-loop system that maintains frequency stability while adapting to changing operating conditions.
3Productivity
If photovoltaic systems are introduced in large numbers into electric power system, then renewable energy penetration is increased, but the stabilization of system frequency becomes difficult due to lack of frequency adjustment function
Solution Approach 1:
The patent applies the copying principle by implementing virtual governor characteristics in photovoltaic systems through control algorithms. This allows large numbers of photovoltaic systems to collectively provide frequency stabilization services similar to traditional synchronous generators, enabling high renewable energy penetration while maintaining system frequency stability.
Solution Approach 2:
The patent implements universality by enabling photovoltaic systems to perform multiple functions: power generation, frequency regulation, and system stabilization. The control algorithm allows photovoltaic systems to simultaneously provide active power while participating in frequency control, making them versatile assets that can replace or supplement traditional generation resources.
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 system effectively stabilizes electric power supply by mimicking synchronous generator behavior, reducing power transmission line flow fluctuations and enhancing system stability, allowing photovoltaic systems to operate optimally within varying conditions.
Implementation Method 1
a direct-current power source (1) including a photovoltaic
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
According to one embodiment, a photovoltaic system and a power supply system include modules (6, 7) configured to detect a node voltage and an output current of a converter (3), an detector (8) configured to obtain an effective power value from the node voltage and the output current, a system condition detector configured to detect a power supply condition in the electric system (5) or the operating conditions of devices included in the electric system (5) and then output a first signal based on a detection result, a setting unit (11) configured to switch the effective power set value to a preset first value or second value on the basis of the first signal and then output the effective power set value, a rotor speed computation unit (12) configured to calculate an angular frequency of an output voltage of the converter (3) on the basis of an output of the detector (8), the effective power set value, and an output of the system condition detector, and a computation unit (15) configured to calculate an output voltage target value of the converter (3) on the basis of the angular frequency, the output current value, and a set voltage value.