Heat Pump Power Control for Stable PV Surplus Utilization
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Solution Overview
Problem
Conventional heat pump hot water supply systems generate reverse power when photovoltaic power generation exceeds consumption, leading to power grid instability and increased energy costs due to inefficient operation and waste of surplus power.
Innovation Solution
A heat pump operation method that adjusts power consumption to follow surplus power only when it can be supplied stably, using control tables and linear interpolation to optimize power usage based on current and stored heat levels, ensuring efficient operation and reducing reverse power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the heat pump operates using all available photovoltaic power when generation exceeds consumption, then the economic benefit is maximized, but reverse power is generated causing power grid instability
Solution Approach 1:
The heat pump operates at partial capacity rather than full capacity by controlling it to consume only a portion of the available photovoltaic power (specifically, when surplus power ≥ predetermined threshold, the heat pump consumes power at a level that maintains its coefficient of performance above a reference value). This partial action allows the system to capture economic benefits from photovoltaic power while preventing excessive reverse power injection that would destabilize the grid.
Solution Approach 2:
The system dynamically adjusts the heat pump's power consumption parameter based on the surplus power level. When surplus power is high, the heat pump operates at higher consumption levels; when surplus power drops below the threshold, operation is restricted. This parameter change strategy optimizes energy utilization while maintaining grid stability.
2Productivity
If the heat pump operates at high power consumption to maximize hot water production, then productivity is improved, but energy efficiency decreases when surplus power is unstable
Solution Approach 1:
The heat pump's power consumption is made dynamic rather than fixed. The control unit continuously monitors surplus power levels and adjusts the heat pump's power consumption accordingly. This dynamic adjustment ensures the heat pump operates efficiently when surplus power is stable and abundant, while reducing or stopping operation when surplus power becomes unstable, thereby maintaining energy efficiency while maximizing productivity during favorable conditions.
Solution Approach 2:
The system implements feedback control by monitoring the coefficient of performance of the heat pump and comparing it against a reference value. When the coefficient of performance exceeds the reference value (indicating efficient operation), the heat pump continues operating at high power consumption. When efficiency drops below the threshold, operation is restricted. This feedback mechanism ensures productivity is maximized only when energy efficiency is maintained.
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 approach stabilizes the power grid by minimizing reverse power flow, reduces energy costs, and optimizes heat pump efficiency by aligning power consumption with available surplus power, thereby enhancing the economic viability of heat pump systems.
Implementation Method 1
A photovoltaic device generates power by transforming solar energy into electricity
Implementation Method 2
A heat pump hot water supply device heats a refrigerant by absorbing heat from the atmosphere and compressing the refrigerant using electricity
Implementation Method 3
A heat pump hot water supply device heats a refrigerant by absorbing heat from the atmosphere
Implementation Method 4
The heat is then transferred to the water via a heat exchanger, creating hot water
Data Source
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AI summary
A heat pump operation method includes: obtaining, on a per time unit basis, generated power which is an amount of power generated by a power generation device, load power which is an amount of power consumed by an electric load, and surplus power which is a difference between the generated power and the load power; and controlling operation of the heat pump, wherein in the controlling, an amount of power consumed by the heat pump for generating heat is adjusted to follow a per unit time increase or decrease in the surplus power when a first condition is met, the first condition being that the surplus power remains greater than or equal to a predetermined threshold value for a given period of time extending back from the present time.