Nanyang Technological University

Fengjiao Cui

Anshuman Tripathi

Abishek Sethupandi

Brihadeeswara Sriram Vaisambhayana

Shuyu Cao

Madasamy Palvesha Thevar

Radhika Sarda

Howe Li Yeo

Hossein Dehghani Tafti

Haonan Tian

Glen Ghias Farivar

A decoupled system for controlling a solid state transformer (SST), the SST comprising an AC-to-DC stage, a DC-to-AC stage, and a DC-to-DC stage, the DC-to-DC stage comprising one or more DC-to-DC converters. The system comprises a stored energy controller coupled to the AC-to-DC stage, the energy controller configured to control the total amount of stored energy within the capacitors of the SST; a power flow controller coupled to the DC-to-AC stage, the power flow controller configured to control power flow in the SST; and one or more energy balancing controllers each coupled to a corresponding DC-to-DC converter, each energy balancing controller configured to balance energy in the corresponding DC-to-DC converter.

Solid state transformer controller

This invention relates to a method of controlling a Solid State Transformer (SST). The method comprises dividing a dual active bridge (DAB) power reference on a Low Voltage (LV) side Direct Current (DC) link voltage to obtain a total DAB reference current; dividing the total DAB current reference by N number of DAB modules to obtain a reference current for each DAB module; in response to SST being in a normal power regulation, determining a deviation of a capacitor voltage at the HV side of each of a k DAB modules with reference from an average voltage from the HV DC bus; determining a current adjustment signal for each of the k DAB modules based on the total DAB reference current and a corresponding deviation of the capacitor voltage of each of the k DAB modules; adding a saturated current adjustment signal together with the reference current for each of the k DAB modules to obtain a total current reference for each of the k DAB modules; and subtracting a sum of the total current reference of each of the k DAB modules from the total DAB reference current to determine a total current reference for an NDAB module.

Dual voltage and current loop linearization control and voltage balancing control for solid state transformer

Growing community of inventors

Singapore, Singapore

Fengjiao Cui