Reducing the losses of solar inverters requires starting from multiple aspects such as design selection, installation and maintenance, and operation management. The following are specific methods and suggestions:
1、 Optimize design and selection
Choose an inverter with an efficient topology structure
Priority should be given to inverters with multi-level transformation topologies (such as DC-DC boost+DC-AC inverter) or new soft switching technologies (such as LLC resonance, phase-shifting full bridge), which can reduce switching losses and conduction losses.
Compare the efficiency curves of different brands of inverters, with a focus on the efficiency under typical loads (such as 50%~80% rated power), and the wider the high-efficiency range, the better.
Match system capacity with load requirements
Avoid long-term operation of the inverter at low load rates (such as<30% rated power), as the fixed losses of the inverter (such as control circuit and fan power consumption) during light loads account for a high proportion, resulting in a decrease in efficiency.
Based on the reasonable selection of photovoltaic module capacity, it is recommended that the rated power of the inverter be 1.1-1.2 times the peak power of the module, balancing overload capacity and efficiency.
2、 Reduce power device losses
Using low loss devices
Switching devices (such as IGBT, MOSFET) should be selected with low on resistance (Rds (on)) and low switching losses, such as silicon carbide (SiC) or gallium nitride (GaN) devices, which have an efficiency 3% to 5% higher than traditional silicon-based devices.
Electrolytic capacitors are selected with long lifespan and low ESR (equivalent series resistance) models to reduce ripple losses and heat generation.
Optimize heat dissipation design
Ensure good contact between power devices and heat sinks, and use thermal grease or phase change materials to reduce thermal resistance.
Reasonably design the air duct to avoid poor heat dissipation caused by fan aging or dust accumulation (high temperature will increase device conductivity loss and shorten lifespan).
3、 Reduce line and electromagnetic losses
Optimize electrical connections
Use short and thick wires to reduce line resistance losses (especially for DC side cables, it is recommended to calculate the cross-sectional area based on current and control the voltage drop within 2%).
Ensure that the terminal connection is firm and avoid poor contact that may cause arcing and additional heating.
Suppress electromagnetic interference (EMI)
Reasonably layout filtering components such as inductors and capacitors to reduce energy loss of EMI filters.
Using high-frequency inductors with lower magnetic core losses (such as nanocrystals and ferrite materials) to reduce hysteresis and eddy current losses.
4、 Intelligent Control and Dynamic Management
Maximum Power Point Tracking (MPPT) Optimization
Ensure that the MPPT algorithm of the inverter is fast and accurate, reducing power loss caused by tracking delay or oscillation (it is recommended to choose an inverter with multiple MPPT channels to adapt to complex component layouts).
Dynamic sleep and sleep wake-up strategy
Under low light conditions, put the inverter into low-power sleep mode, turn off non essential circuits (such as fans and drive power), and reduce standby losses (typical standby losses should be<1.5W).
When the illumination is enhanced, quickly wake up and restore MPPT tracking to reduce energy loss.
Dynamic load matching
For off grid inverters, adjust the output power according to real-time load to avoid the phenomenon of "big horse pulling small car" (such as switching to energy-saving mode when unloaded or lightly loaded).
5、 Regular maintenance and fault prevention
Cleaning and Inspection
Regularly clean the dust inside the inverter to prevent overheating caused by blocked heat dissipation holes (it is recommended to use compressed air or a vacuum cleaner every 6-12 months).
Check if the capacitor bulges and if the inductor makes any abnormal noise, and replace aging components in a timely manner.
Software upgrade and parameter calibration
Timely update inverter firmware, optimize control algorithms and loss management strategies.
6、 System level collaborative optimization
Photovoltaic module matching
Ensure that the orientation and inclination of the components are consistent to avoid array mismatch caused by local shadows or aging (mismatch can cause the inverter to operate at low efficiency points).
Using string inverters or optimizers to reduce power mismatch losses between series branches.
Energy storage system coordination
Combined with energy storage batteries, switch to battery charging and discharging mode during periods of low inverter efficiency (such as transitional lighting) to avoid frequent start stop losses.
Through the above measures, the overall loss of the inverter can be controlled within 5%, and for high-efficiency models, it can even be lower than 3%. In practical applications, it is necessary to comprehensively optimize the system scale, cost budget, and usage scenarios, and prioritize improving the high proportion of loss links (such as switch losses and line losses).
