PV-Powered Pump Inverter Frequency Control
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Solution Overview
Problem
Existing solar-powered pumping systems are complex and expensive due to the need for multiple electrical components when using photovoltaic panels to drive alternating current motors, as they require conversion from DC to AC voltage.
Innovation Solution
A method and arrangement where the DC voltage from photovoltaic panels is directly used to control the output frequency of an inverter connected to an AC motor, maintaining a constant voltage/frequency ratio below a set limit (Vboost) and increasing frequency to keep voltage constant when exceeding the limit, allowing efficient energy utilization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If photovoltaic panels are used to drive AC motors through DC-AC conversion, then the pump can be operated with solar power, but the system structure becomes complex and expensive with multiple electrical components
Solution Approach 1:
The patent extracts and eliminates the battery and charge controller components from the traditional solar pump system. By directly connecting the photovoltaic panels to the AC motor through a DC-AC inverter, the system removes unnecessary energy storage and regulation components, simplifying the overall structure while maintaining solar power operation capability
Solution Approach 2:
The DC-AC inverter is designed to perform multiple functions: it converts DC from photovoltaic panels to AC for the motor, provides motor control, and enables direct coupling without requiring separate battery management systems. This multi-functionality reduces the total component count and system complexity
2Ease of operation
If multiple electrical components are used for DC to AC conversion, then the pump can be operated, but the system becomes vulnerable and expensive
Solution Approach 1:
The patent merges the functions of multiple electrical components (photovoltaic panels, inverter, and motor control) into an integrated system. The DC-AC inverter serves as the central component that handles both power conversion and motor control, reducing the number of connection points and potential failure sources in the system
3Power
If the voltage from photovoltaic panels varies, then the available power changes, but maintaining constant torque and maximizing power delivery becomes difficult
Solution Approach 1:
The patent implements dynamic control of the DC-AC inverter that continuously adapts to varying photovoltaic panel voltage. The inverter adjusts its operating parameters in real-time to maintain optimal power transfer and constant torque delivery to the motor, regardless of input voltage fluctuations from the solar panels
Solution Approach 2:
The system changes operating parameters (frequency, voltage, current) of the DC-AC inverter based on the instantaneous voltage from the photovoltaic panels. By dynamically adjusting these parameters, the system maintains constant torque and maximizes power delivery even when the input voltage varies with solar conditions
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
This simplifies the system structure while fully utilizing photovoltaic panel energy, maintaining constant torque and maximizing power delivery to the pump, even when voltage does not reach its maximum value, by adjusting the inverter frequency based on input voltage.
Implementation Method 1
a photovoltaic panel system electrically connected to feed DC power to an inverter
Implementation Method 2
an inverter, an output of which is electrically connected to the AC motor
Implementation Method 3
a pump arranged to be rotated with an AC motor
Data Source
AI summary
A method and arrangement for operating a pump system are disclosed, the pump system including a pump arranged to be rotated with an AC motor, an inverter, the output of which is electrically connected to the AC motor, and a photovoltaic panel system electrically connected to feed DC power to the inverter. The method can include setting a voltage limit, and determining continuously voltage obtained from the photovoltaic panel system. When the determined voltage of the photovoltaic panel system is below the set voltage limit, frequency of the inverter can be controlled such that the ratio between output voltage of the inverter and the output frequency is substantially constant. When the determined voltage of the photovoltaic panel system exceeds the voltage limit, the inverter frequency can be controlled for keeping voltage of the photovoltaic panel system substantially at the voltage limit.