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II. CONDITIONER TOPOLOGIES
static
switch
DCLink
Load
Power
Supply
series
PWM
converter
Parallel
PWM
convert
er
Fig. 1. Conditioner Topologies: UPQC and Line-interactive UPS system. 1
II. CONDITIONER TOPOLOGIES
- When the UPS system is implemented, an additional static
switch ( sw ) is used to provide the disconnection between the
UPS system and the power supply.
- The series PWM converter must behave as a current
source with a high enough impedance to isolate the
line from the load harmonic currents.
- The parallel PWM converter must behave as a voltage
source with a high enough admittance to absorb the
harmonic currents of the load
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III. SRF - BASED ALGORITHM
- The SRF-based algorithms can be used to perform load
unbalance compensation or to independently compensate
each of the three phases. When the load unbalance
compensation is implemented the source currents become
balanced and sinusoidal
- However, when the phases are individually controlled the
source currents will be sinusoidal but unbalanced
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III. SRF - BASED ALGORITHM
A. SRF-Based Algorithm Applied to Single-Phase Loads
- The SRF-based algorithm applied to single-phase loads is
shown in Fig. 2.
- Measuring the load current of any phase (iL)
provides
the
two-phase stationary reference frame β quantities (i ,i β)
- Low Pass Filter (LPF). The total direct current component
(idTdc), is reached by adding iddc to the component obtained
from the DC-link controller (idc ).
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III. SRF - BASED ALGORITHM
A. SRF-Based Algorithm Applied to Single-Phase Loads
LPF- Low-Pass Filter
PLL - Phase-Locked
Loop
Fig. 2. SRF-based algorithm for 1-phase load.
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III. SRF - BASED ALGORITHM
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III. SRF - BASED ALGORITHM
- Independent Phase Control
Compensation
- DC-bus Control Block Diagram
- Load Unbalance Compensation.
Fig.3
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