Energy Storage Frequency Converter for Microgrid Frequency Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Unsatisfactory reliability of regional power grids affects the production and operation of frequency conversion equipment in hydrometallurgical plants due to frequent power cuts, fault shocks, and frequency fluctuations, leading to prolonged startup processes and high energy consumption.
Innovation Solution
Implementing an energy storage frequency converter with an energy storage unit, AC-DC converters, and an inverter, connected to a microgrid, which actively detects frequency changes and controls circuit breakers to manage power distribution, including the use of generators, renewable energy, and energy storage units to stabilize power supply.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the plant relies on the external power grid for operation, then the equipment can operate with external power supply, but the production and operation are affected by frequency fluctuations and power failures
Solution Approach 1:
The patent introduces an energy storage frequency converter as an intermediary device between the external power grid and the variable frequency motor. This converter includes an energy storage unit that decouples the motor from grid frequency fluctuations, allowing the motor to operate stably while the converter handles frequency conversion and energy buffering.
Solution Approach 2:
The energy storage unit is pre-charged from the grid when power is available, storing energy in advance. When grid frequency fluctuates or power fails, the pre-stored energy is immediately discharged to maintain continuous operation, preventing the harmful effects of frequency variations before they can impact the motor.
2Reliability
If the plant uses a generator for independent power supply, then the equipment can operate independently from the external grid, but the startup process requires long soft start time and high energy consumption
Solution Approach 1:
The energy storage unit is pre-charged during periods when power demand is low or grid power is available, accumulating energy in advance. During motor startup, this pre-stored energy is immediately released to provide the high starting current needed, eliminating the need for prolonged soft-start periods and reducing total startup time.
Solution Approach 2:
The system dynamically adjusts the operating mode of the energy storage unit based on real-time power conditions. During startup, the converter switches to draw power from the energy storage unit, providing dynamic high-power output. During normal operation, it transitions to grid power with energy storage providing buffering, optimizing both startup performance and operational efficiency.
3Reliability
If the plant uses a generator for power supply, then the equipment can operate independently, but the energy consumption during startup is relatively high
Solution Approach 1:
The energy storage unit accumulates energy in advance during low-demand periods or when grid power is available. During motor startup, this pre-stored energy is immediately released, providing the high starting current without requiring continuous high energy consumption from the generator, thus reducing total startup energy usage.
Solution Approach 2:
The energy storage unit operates in periodic charge-discharge cycles. It charges from the grid or generator during normal operation when power is abundant, then discharges during startup or peak demand periods. This periodic action smooths out energy consumption peaks, reducing the total energy burden on the generator during startup phases.
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
Stabilizes the operation and production of frequency conversion equipment by promptly responding to frequency fluctuations and power failures, reducing downtime and energy consumption.
Implementation Method 1
an energy storage unit, a first AC-DC converter, and an inverter... The energy storage unit and renewable energy are both connected to a DC bus
Implementation Method 2
An input end of the first AC-DC converter is connected to an external power grid via an AC bus... An output end of the first AC-DC converter is connected to an input end of the inverter
Implementation Method 3
An output end of the first AC-DC converter is connected to an input end of the inverter, and an output end of the inverter is connected to a variable frequency motor
Data Source
AI summary
A method for controlling a microgrid of a hydrometallurgical plant based on an energy storage frequency converter includes: controlling the opening and closing of a first circuit breaker and a second circuit breaker based on frequency change data of an AC bus in a plant microgrid. The energy storage frequency converter includes an energy storage unit, a first AC-DC converter, and an inverter. An input end of the first AC-DC converter is connected to an external power grid through an AC bus, and a first circuit breaker is provided between the first AC-DC converter and the external power grid. An input end of the inverter is connected to an output end of the first AC-DC converter, and an output end is connected to a variable frequency motor. The energy storage unit is connected between the output end of the first AC-DC converter.