Practical design issues of multi-loop controller for a telecom rectifier

Dynamic Modeling and Analysis of Current‐Output Converters

“…The rectifiers in the Telecom DC-UPS applications (Figure 7.1) [4] are normally operating at voltage-output mode, and when recharging the parallel connected battery, the current-output mode is automatically switched on. The required control system may be implemented either by using independent controllers for the voltage and current loops or using a cascaded configuration, where the voltage loop is the inner loop and the current loop the outer loop.…”

“…The overload limiting is typically implemented using either constant-current or modified-constant-power limiting schemes as illustrated in Figure 7.2 [3][4][5]. The constant-current limiting can be accomplished either by using only the output current signal (i.e., single loop) or both the output voltage and the output current in cascade where the inner loop is the voltage loop and the outer loop the current loop.…”

Basis for Dynamic Analysis and Control Dynamics

“…The open-loop condition is defined to be such a condition where the external feedback from the controlled output variable (i.e., usually the output voltage or current) does not affect the dynamic behavior of the converter [1]. Sometimes the converter may change the operation mode from the voltage output to the current output [4] to protect itself from damage due to excess load current generated for example by a storage battery [5] when charged. Sometimes the converter may change the operation mode from the voltage output to the current output [4] to protect itself from damage due to excess load current generated for example by a storage battery [5] when charged.…”