Power Electronics pptx

[...]... and a root-mean-square (rms) value in AC quantities If there is a 1 2 Power Electronics Power input Power output Power processor vi vO ii iO Control signal Reference FIGURE 1.1 Load Measurement Controller Block diagram of a power electronics system possibility of confusion, the subscript avg or rms is added explicitly The average power is always indicated by P Usually, the input voltage and current... harmonic voltage, Average/rms nth-order harmonic voltage (V) 8 Power Electronics 1.1.4 Factors and Symbols Used in Switching Power Systems Switching power systems, such as power DC/DC converters, power PWM DC/AC inverters, soft-switching converters, and resonant converters, are widely used in power transfer equipment In general, a switching power system has a pumping circuit and several energystorage... amplitude, and φ the phase-delay angle We define the power factor (PF) as PF = cos φ (1.11) PF is the ratio of real power (P) to apparent power (S) We have the relation S = P + jQ, where Q is the reactive power The power vector diagram is shown in Figure 1.3 We have 5 Introduction S = P + jQ jQ f P FIGURE 1.3 Power vector diagram the relations between the powers as follows: S = VI ∗ = |S| = V2 = P + jQ... international conferences His present research interests include power electronics and DC & AC motor drives with computerized artificial intelligent control (AIC) and digital signal processing (DSP), and digital power electronics He is currently the associate editor of both IEEE Transactions on Power Electronics and IEEE Transactions on Industrial Electronics He is also an international editor for the international... impulse interference 10 Power Electronics If there are power losses and η < 1, ξ is defined as ξ= τd CIR = τ η[1 + CIR(1 − η/η)]2 (1.39) If there are no power losses, η = 1, Equation 1.39 becomes Equation 1.38 Usually, if the power losses (the lower efficiency η) are higher, the time constant ratio ξ is smaller since CIR > 1 From this analysis, most switching power systems with lower power losses possess... tan−1 ωCR (1.7) 4 Power Electronics We define the circuit time constant τ as τ = RC (1.8) Summary of the Symbols Symbol C f i, I L R p, P q, Q s, S v, V Z φ η τ ω 1.1.2 Explanation (measuring unit) Capacitance (F) Frequency (Hz) Instantaneous current, Average/rms current (A) Inductance (H) Resistance (Ω) Instantaneous power, Rated/real power (W) Instantaneous reactive power, Rated reactive power (VAR) Instantaneous... Average/rms fundamental current (A) Instantaneous nth-order harmonic current, Average/rms nth-order harmonic current (A) Current amplitude (A) Power factor (leading/lagging %) Instantaneous reactive power, Rated reactive power (VAR) Instantaneous apparent power, Rated apparent power (VA) Time (s) Total harmonic distortion (%) Instantaneous fundamental voltage, Average/rms fundamental voltage (V) Instantaneous... in power electronics and provides useful and concise information with regard to advanced converters It contains more than 200 topologies concerning advanced converters that have been developed by the authors Some recently published topologies are also included The prototypes presented here demonstrate novel approaches that the authors hope will be of great benefit to the area of power electronics Power. .. there are power losses and η < 1, τ is defined as τ= 2T × EF 1−η 1 + CIR 1 + CIR η (1.35) If there are no power losses, η = 1, Equation 1.35 becomes Equation 1.34 Usually, if the power losses (lower efficiency η) are higher, the time constant τ is larger since CIR > 1 The damping time constant τd of a switching power system is a new concept that describes the transient process If there are no power losses,... power losses and η < 1, τd is defined as τd = 2T × EF CIR 1 + CIR η + CIR(1 − η) (1.37) If there are no power losses, η = 1, Equation 1.37 becomes Equation 1.36 Usually, if the power losses (lower efficiency η) are higher, the damping time constant τd is smaller since CIR > 1 The time constant ratio ξ of a switching power system is a new concept that describes the transient process If there are no power . approaches that the authors hope will be of great benefit to the area of power electronics. Power electronics is the technology behind the conversion of electrical. 1 1.1.1 Symbols Used in Power Systems 1 1.1.2 Factors and Symbols Used in AC Power Systems 4 1.1.3 Factors and Symbols Used in DC Power Systems 7 1.1.4 Factors