Author: Prof.dr.ing. Mihaela Popescu
Faculty of Electrical Engineering
Department of Electrical, Energy and Aerospace Engineering - Craiova
Year of publication: 2020
What are static converters?
Static converters (CS) are equipment whose power part contains semiconductor power elements.
Uncommanded static converters they are built with uncontrolled semiconductor devices (diodes) and perform the conversion of electrical energy into electrical energy, modifying its parameters, without allowing the regulation of the average power transmitted to the load.
What does the paper present?
The course refers to ordered static converters which are built with controlled semiconductor elements and which, in addition to converting electricity, allow the control of the average power transmitted to the load.
The structure of the paper
CHAPTER I - Introductory notions
- The place of static converters in the energy flow
- Characterization of electricity at the output of the static converter
- Classification of static converters
CHAPTER II - Semiconductor power elements: diode and thyristor
- Introduction
- diode
- thyristor
- Gate Lock Thyristor (GTO)
- Bipolar Power Transistors (BPT)
- Field effect power transistors (power MOSFET)
- Bipolar transistors with IGBT insulated base
- SITh static induction thyristors
CHAPTER III - Choice and verification of power semiconductor elements
- Losses in semiconductor power elements
- Choice of power semiconductor elements
CHAPTER IV - Protection of power semiconductor elements
- Protection of thyristors against switching overvoltages
- Protection of static converters connected to the AC network
- Short circuit protection of thyristors
CHAPTER V - Static converters AC to DC (rectifiers)
- Introduction
- The principle and general theory of phase-controlled rectifiers
- Interrupted current regime
- Sizing of the filtering inductance
- Basic diagrams of the ordered rectifiers
- Bidirectional rectifiers
- Control of rectifiers with natural switching
CHAPTER VI - Alternative voltage variators
- Single-phase variators
- The principle, the scheme of principle
- The case of a resistive load
- The case of a purely inductive pregnancy
- The case of a resistive-inductive load
- Characteristic sizes
- Three-phase variators
CHAPTER VII - Cycloconverters
- The principle and the scheme of principle
- Cyclo-converter control
- Case study - cyclo-converter made with 3-pulse rectifiers
- Phase control of static converters as - with natural switching
CHAPTER VIII - DC voltage variators
- The voltage inverter continues downhill
- The principle and the scheme of principle
- Uninterruptible current characteristics
- Expression of current through load
- The limit of the interrupted current area
- Interrupted current regime
- The appearance of the interrupted current regime
- External and control characteristics in interrupted current mode
- Filter inductance sizing elements
- Calculation of the inductance required to limit the pulsations
- Calculation of the inductance required to avoid VTC operation in interrupted current mode
- Practical schemes of descending VTC
- VTC with IGBT transistor
- VTC with thyristors and reverse polarization lock (VTC-U)
- VTC with thyristors and current deflection switch-off (VTC-I)
- Other topologies of VTC-U and VTC-I
- The voltage inverter continues downhill
- Schematic diagram, control, operation
- Operation in uninterrupted current mode
- The limit of the interrupted current area
- Characteristics in interrupted current regime
- Order
- DC voltage converter in four dials
CHAPTER IX - Indirect static voltage and frequency converters
- The principle and the scheme of principle
- Single phase inverters with amplitude modulation
- The principle, the scheme of principle
- Single-phase midpoint inverter
- Single-phase bridge inverter
- Three-phase voltage inverters with amplitude modulation
- Scheme of principle, command, waveforms
- Characteristic sizes
- Harmonic analysis of line voltage
- Control block structure
- Three-phase current inverters with amplitude modulation
- Scheme of principle, command, waveforms
- Characteristic sizes
- Control block structure
- Static voltage and frequency converters with duration modulation
- Sinusoidal modulation
- Voltage inverter with sinusoidal modulation
- Voltage inverter with trapezoidal modulation
- Frequency modulation
- Vector modulation
- Closed loop modulation strategies
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