Inverter & Generator Harmonics
The Integration Challenge
Using a small generator to back up your inverter system is a logical and common requirement. However, it is not always an easy integration due to the vast array of different inverters and generator alternators on the market.
From our own experience and extensive testing, we have found that certain inverters struggle to work with our smaller generators that utilize the Datakom DKG-116 or Smartgen MGC100 controllers coupled with a 3000RPM, 2-Pole alternator. This incompatibility is caused by harmonic feedback.
These specific controllers do not filter out high-frequency harmonics. When these harmonics enter the main power cable, they cause a ripple effect that pushes the voltage and frequency readings up on both the inverter and the generator. As a safety measure, the inverter will disconnect the AC input, and the generator will shut down due to an overspeed or overvoltage error.
The harmonic feedback issue is present in the following smaller units:
- SOL-I-AX-5K / SOL-I-AX-5KP / Axpert King
- MKS-5K 48v-KING
- SOL-I-AX-5P / SOL-I-AX-5P64 / MKS-5K
- SOL-I-AX-3MPlus24 / MKS-3K-Plus-24
- SOL-I-AX-3MPlus48 / MKS-3K-Plus-48
- Most standard Growatt Inverters
What Are Harmonics?
Harmonic interference consists of additional waveforms running on the same electrical line at a higher frequency. This distortion causes the voltage and frequency readings on both the generator and inverter to artificially spike, forcing them to exceed their safety pre-sets and shut down. These safety parameter windows cannot be adjusted higher to accommodate the feedback.
Read More About AC Harmonics