Question 10.SP.15: By SPICE methods, model the buck-boost converter of Fig. 10-......

Schaum’s Outline of Electronic Devices and Circuits [1089587]

By SPICE methods, model the buck-boost converter of Fig. 10-6 with $f_s = 30 kHz, D = 0.4, L = 70 μH, C = 100 μF$ , and $R_L = 10 Ω$ . Use the model to generate a set of waveforms analogous to Fig. 10-7.

10.7

10.6

Step-by-Step

The 'Blue Check Mark' means that this solution was answered by an expert.
Learn more on how do we answer questions.

The netlist code is shown below where the initial conditions on inductor current and capacitor voltage were determined after running a large integer number of cycles to find the repetitive values.

Prb10_15.CIR
* BUCK-BOOST CONVERTER
* D=DUTY CYCLE, fs=SWITCHING FREQUENCY
.PARAM D=0.4 fs=30e3Hz
V1 1 0 DC 15V
SW 1 2 4 2 VCS
VSW 4 2 PULSE(0V 1V 0s 5ns 5ns {D/fs} {1/fs})
L 2 0 70uH IC=0.229A
D 3 2 DMOD
C 0 3 100uF IC=10.02V
RL 0 3 10ohm
.MODEL DMOD D(N=0.01)
.MODEL VCS VSWITCH(RON=1e-6ohm)
.TRAN 1us 0.166667ms 0s 100ns UIC
.PROBE
.END

Execute 〈Prb10_15.CIR〉 and use the Probe feature of PSpice to plot the waveforms of Fig. 10-15.

10.15

Related Answered Questions

Question: 10.SP.13

A lossless buck-boost converter with continuous inductor current supplies a 10 Ω load with a regulated output voltage of 15 V. The input voltage is 12 V. Determine the value of (a) duty cycle, (b) input power, and (c) average value of input current. ...

Verified Answer:

(a) Solve (10.9) for D to find

G_{V} = {\fr...

Question: 10.SP.11

Let Rx be the inherent resistance of the inductor L for the boost converter of Fig. 10-4 and derive an expression for the actual voltage gain (G′V = V2/V1) that is valid for continuous inductor current. Treat V2 as constant in value. Assume that iL can be described by straight line segments. ...

Verified Answer:

Figure 10-12(a) represents the circuit of Fig. 10-...

Question: 10.SP.10

A boost converter with continuous inductor current is fed from a 12-V source with a 60 percent duty cycle while supplying a power of 60 W to the connected load. Determine (a) the output voltage, (b) the load resistance, and (c) the load current. ...

Verified Answer:

(a) By (10.7),

G_{V} = {\frac{V_{2}}{V_{1}}...

Question: 10.SP.9

For the buck converter of Example 10.5, (a) calculate the percent voltage ripple by (4) of Problem 10.8 and (b) formulate a SPICE simulation to numerically determine the percentage ripple. ...

Verified Answer:

(a) By (4) of Problem 10.8 with the values of Exam...

Question: 10.SP.8

For work to this point, the output voltage of the buck converter has been assumed constant (v2 ≃ V2) for sufficiently large values of C; however, since iC is a time-varying quantity, v2 does display a small peak-to-peak ripple Δv2. Use the change in capacitor charge (QC), under the assumption that ...

Verified Answer:

Since

v_2 = Q_C/C

, the total increm...

Question: 10.SP.6

Determine a set of equations that describe the instantaneous inductor current iL(t) over a period Ts for the buck converter. ...

Verified Answer:

Refer to

i_L

and

v_L

...

Question: 10.SP.3

Assume the buck converter of Fig. 10-2 is lossless so that the input power (Pin) is equal to the output power (Po). Derive an expression for the current gain GI = I2/I1. ...

Verified Answer:

The input power and output power are found by use ...

Question: 10.SP.14

If Rx is the inherent resistance of the inductor L for the buck-boost converter of Fig. 10-6, derive an expression for the actual voltage gain (G′V = V2/V1) that is valid for continuous inductor current. Assume that iL is described by straight line segments. ...

Verified Answer:

The circuit of Fig. 10-14(a) represents the circui...

Question: 10.SP.12

Use SPICE methods to model the boost converter of Fig. 10-4 with fs = 20 kHz, D = 0.25, L = 50 μH, C = 100 μF, and RL = 7.5 Ω. From the model, generate a set of waveforms analogous to Fig. 10-5. ...

Verified Answer:

The netlist code is shown below where the initial ...

Question: 10.SP.7

Find the maximum and minimum values of the inductor current for the buck converter of Problem 10.2 if the duty cycle D = 0.6 and V1 = 24 V. ...

Verified Answer:

Since

D = 0.6 \gt D_{\mathrm{min}} = 0.4286...