Standby (Idle) mode

The functionality of Standby mode is to stop the IGBT switching when the system is supposed to stop exporting or importing power to/from the utility grid, with an optimized power consumption in order to save energy.

Entering Standby mode will NOT improve the speed of Starting the inverter, or the speed of Grid-tied/Off-grid toggling.

The inverter has 3 capacitors rated 20µF in wye topology as the high frequency PWM current filter. And the capacitive reactive power would be

$$\frac{(277V)^{2}}{\frac{1}{j\omega \times 20 \mu F}}\times3=1.73 kVAr$$

In the previous firmwares when standby(idle) mode was not implemented, the controlling software will compensate this 1.73kVAr reactive power with the PWM current whenever. But since the newest updating, when the active power is set to around 0, the software will enter standby(idle) mode to save energy, by stopping IGBT switching, so the reactive power generated by the capacitor filter can NOT be compensated.

There are two ways to enter or exit Standby (Idle) mode

•  Write 1 to register 655 to enter Standby mode
•  Write 0 to 655 to exit Standby mode

Once the PWS2-30K receives the flag from the BMS that indicates

•  the battery is fully charged
•  the battery is empty discharged,

the PWS2-30K will enter standby mode automatically. Once reversed operation is commanded, the PWS2-30K will exit standby mode automatically:

•  Battery is fully charged, commanded to discharge
•  Battery is empty discharged battery, commanded to charge

The time delay for exiting standby mode is 30ms.