Table 3 Fact devices and their impacts on power quality and electric vehicle charging system
S. no | Filter and fact devices | Features | Drawbacks | Positive impacts and control features in power quality and electric vehicles system |
|---|---|---|---|---|
1 | Efficient, low ripple factor, reliable, high gain, bleeder resistance improves voltage regulation and filtering action | Require tuning of LC circuit, limited standard sizes, L filter is bulky, Low output DC voltage | Reduction in DC ripple, AC side harmonics, reduced filter VA rating, prevent injection of low order current harmonics into ac mains, reduce electromagnetic interference problem in EV system | |
2 | Small in size, more energy capacity compared to UPS, less cost, higher capacity, less maintenance, voltage balancing capability | Difficult to protect the devices during short circuit due to connected in series, no battery | Very fast response, Precise voltage regulation, Improve and correct short voltage reductions, controlled real and reactive power at load side, compensate power quality issues, i.e., voltage sag and swell when integrated with energy storage devices in EV charging system, absorb harmonic current, controlled charging | |
3 | Less no of components, power easily scaled, better electromagnetic compatibility, lower switching loss, boost voltage, reduce voltage stress, THD is low, simple control of active and reactive power | Capacitor and clamp diode is in large number, i.e., system bulky, efficiency poor, high cost, capacitors voltage unbalance | Staircase waveform quality, reduced harmonic distortion, reduce electromagnetic interference problem in EV system, less voltage distortion, operate in bidirectional way in EV system, Increase reliability | |
4 | Extension of UPFC, combination of series controller and unified controller, control power flow of multiple lines, switches off capacitor bank, current, voltage when excess, control and optimize of transmission line | More no of series converter makes system bulky, less control of capacitor voltage, | Increase stability of grid using Internet of things, improved voltage profile, reduced power loss, enhances dynamic response when combine with superconducting magnetic energy storage (SMES), robustness, reactive power control, damp oscillation | |
5 | Component smaller than SVC, faster response time, dynamic voltage control, better characteristics, robust and simple, flexible algorithm | More losses, high cost, no harmonic suppression | Controlling voltage, VAR compensation, damp oscillation, dynamic stability, minimize total real power loss, power factor correction | |
6 | STATCOM with storage [98] | Wide operating range, lower rating than SVC, dynamic voltage control, better characteristics, robust and simple, flexible algorithm, component smaller than SVC, faster response time | More loss, high cost, large DC source required to charge the capacitor, no harmonic suppression | Interface with real power sources, like battery, fuel cell or SMES, controlling voltage, VAR compensation, damp oscillation, automatic gain controller, provide smooth integration of renewable energy, minimize total real power loss and power factor correction in EV system |
7 | Improve transient, Smoother control, faster response due to no inertia, improve system capability | Slower than STATCOM, Not interface with energy storage sources, expensive, limited overload capability | Control reactive power, overvoltage and dynamic performance of grid, reduce fluctuation on grid voltage, stabilize system, minimize energy loss, improve voltage deviation | |
8 | High reliability, low maintenance, improve transient stability, faster response, static operation | Large DC source required to charge the capacitor, no harmonic suppression | Control damping oscillation, Interface with real power sources, like battery, fuel cell or SMES, controlling voltage, VAR Compensation | |
9 | Combination of STATCOM and static series compensator, high level of voltage and current achieve, redundancy is possible, bidirectional flow capability, real time control, flexible, capacity expansion possible | System cost high, control complexity when DC linked separated, interruption in voltage not possible, required large number of diodes, inverter and capacitor which makes system bulky, conduction and switching loss high | Control voltage, current, phase and power flow, Control active and reactive power, VAR compensation, damping oscillation, transient and dynamic stability, better voltage regulation than SSSC, minimization of losses, voltage stability, improves dynamic stability of system | |
10 | Provide reactive power compensation, power flow control, System impedance control | Phase shift error increase due to linearization | Transient and dynamic stability improvements, better voltage regulation, improves power transfer capability, Power compensation and low frequency power oscillation, Enhances system load ability | |
11 | Connected in series with transmission line through transformer, eliminate bulky passive component capacitors and inductor, injected voltage managed independently, satisfactory work with high load and low load, increase or decrease transferable power | Expensive, costly, mal operation of relay if degree of compensation and location is not proper | Power factor correction, load balance, reduce harmonic distortion, Series voltage sag compensation, regulate power flow, limit short circuit current, mitigate sub synchronous resonance oscillation in grid | |
12 | Improve system stability, provide nonlinear switching behavior of thyristors, decrease dc offset voltage, improve voltage profile | High level of harmonics due to non-symmetrical harmonics, heating, and additional power losses issue | Control active power flow, suppress oscillation, decrease Dc offset voltages, control power flow, improve the transient stability, limit fault current, mitigate sub synchronous resonance | |
13 | Compensate, regulate and damp oscillation power system, decrease dc offset | Heating issue, power loss, switching and conduction loss, costly | Control current, improve transient and dynamic stability, | |
14 | Connected in series with grid system, easier to tune, smaller in size, harmonic isolation and harmonic damping, reduce power loss, reliable operation, less dependency on inductors | Large DC power supply require, oscillation, expensive, not handle large amount of power, handle low and moderate frequency | Reactive power compensation, control voltage, mitigate current unbalance, Sag, swell, reduce current harmonics, mitigate harmonic distortion in distribution network, reduce dc ripple, ac side harmonics, and filter VA ratings | |
15 | Connected in parallel with grid system, compensate unbalance current and fluctuating current, easy installation, easy to connect parallel line, low implementation cost | Not applicable for high order harmonic, large DC power supply require, large capacitor makes system bulky and expensive, smaller inductor increase ripples | Reactive power compensation, mitigation of current unbalance, reduce harmonic propagation, and interharmonic, improve system performance, i.e., reduce current and voltage distortion in distributed grid | |
16 | Virtual Coordinate System [120] | Combine effect of phase locked frequency multiplier and instantaneous reactive power theory improve charging quality of electric vehicle, reliable operation, response increase | Typical have fast locked problem in PLL multiplier, overshoot and instability, power dissipation in PLL, not accurate under high bandwidth condition, Sensitive to harmonics | Reduced impact of volatile energy, reduced distortion and fluctuation of charging current, improve charging quality of electric vehicle, reduce fluctuation of output voltage, reduce distortion of access current, enhances life of battery and charging components of electric vehicle charger |