A Comparison of PowerElectronics Simulation Tools
ABOUT THE AUTHORS
José
Rodríguez has a Doktor Ingenieur degree in Electrical
Engineering. He has worked for 25 years in power electronics doing
research, teaching, and in industrial applications. Dr. Rodriguez
has more than 100 publications in the powerelectronics field. He
is currently professor and head of the Department of Electronics at
the Universidad Técnica Federico Santa María.
Alejandro Weinstein is an electrical engineer and graduate student at the Department of Electronics at Universidad Técnica Federico Santa María. Pablo Lezana is a graduate student at Universidad Técnica Federico Santa María. 

Modern powerelectronic systems exhibit a strong interaction between voltage sources, loads, power semiconductors, and control circuits. This element interaction is complex, due to the nonlinear behavior of the power semiconductors and the different magnitudes of the circuit's time constants. Due to this complex interaction, simulation is almost the only way to study the behavior of powerelectronic systems prior to prototyping.
Several simulators, each with different capabilities, are available. We assessed four types of commercial simulation programs designed to simulate power electronic systems on a singlephase boost rectifier circuit:
 Equation solver: Matlab: Simulink Version 5.3.0
 Circuitequation solver: Matlab: Power System Blockset Version 1.1
 General circuit solver: PSpice (Microsim 8)
 Powerelectronicsspecific circuit solver: Simplorer 4.2
 A fast currentcontrol loop that can be implemented with a BangBang controller or a proportionalintegrative (PI) controller plus pulsewidthmodulation (PWM) modulator.
 A slow DC voltagecontrol loop.
 Use of fastswitching power semiconductors.
The purpose of the boost rectifier is to generate a controlled DC voltage (v_{o}) and a sinusoidal input current (I_{s}).
Figure 1: Boostrectifier power circuit (a) and control system (b).
These tasks are done by changing the conduction state of transistor T1, which operates in the switching mode (on/off). When T1 is on, the singlephase power supply is shortcircuited through inductance L, increasing current I_{L}. When T1 is off, the inductor current flows through diode D, charging capacitor C. In this case, the inductor current decreases due the output voltage (v_{o}). This voltage should be at least 10% higher than the peak value of the source voltage (v_{s}) in order to assure good control of the current.
The equations describing this rectifier are:
Figure 1b shows the control system of the rectifier, which includes a PI controller to regulate the output DC voltage. The reference value I_{Lref} for the inner control loop is the product of the output of the PI controller and the normalized voltage v_{f}. A hysteresis controller provides a fast control for inductor current I_{L}.
Voltage Source  v_{f}  220 V, 50 Hz 
Inductor  L  6 mH 
Resistor  R  50100 
Capacitor  C  1 mF 
Voltage Reference  v_{o ref}  380 V 
Hystersis  1.2 
Table 2: Circuit values used in simulating the singlephase boostrectifier power circuit
The simulation with MatlabSimulink was performed with a fixedstep algorithm to avoid convergence problems. In PSpice, the voltage tolerance (VNtol) was 10^{6}, while the maximum number of iterations used in Simplorer was 20.
Variable Step  Variable/Fixed Step  
PSB  PSpice  Simulink  Simplorer  
Algorithm  Ode15s (stiff/NDF)^{*}  Trapezoidal  Ode5 (Dormand/Prince)  Euler 
Absolute Tolerance  Auto  10^{3}  
Relative Tolerance  10^{3}  1.5 x 10^{3}  
Max. Step Size  10^{4}  10^{5}  10^{3}  
Min. Step Size  10^{5} 
^{*} Other algorithms are available, but this one is recommended
Table 3: Simulation conditions for the singlephase boostrectifier power circuit.
All the simulators in this comparison generated the same results, shown in Figures 5 and 6. Figure 5 shows the dynamic behavior of the output voltage v_{o} and inductance current I_{L} in response to stepchanges in the load (from 100 to 50 and back to 100 ). Table 4 shows the time needed to simulate the rectifier during this operation. Figure 6 presents the steadystate behavior of input voltage and current.
Figure 5: Dynamic behavior of inductor current (I_{L}) and output voltage (v_{o}) due to changes in load resistance.
Figure 6: Steadystate behavior of input voltage (v_{s}) and input current (I_{s}).
Simulation Time (sec) 
Difficulty of Use 
Control Elements 

Simulink  10  High  Very Good 
PSB  293  Medium  Very Good 
PSpice  104^{*}  Medium  Bad 
Simplorer  53  Low  Good 
Table 4: A comparison of the four simulators shows substantial differences in run times, difficulty of use, and controlelement availability. All simulations were done on a Pentium III 500 MHz computer with 64 Mbytes of memory. ^{*} Does not include display time.
The Matlab environment is well known for its very powerful control tools. Simplorer can use these tools through the Sim2Sim module to increase its control library—this capability lets Simplorer implement the standard controllers used in power electronics. Finally, PSpice's control features are limited and are more difficult to implement, making PSpice a poor simulation alternative. Table 4 shows that MatlabSimulink is the most difficult to use, while Simplorer is the simplest.
Given the previously stated particularities of powerelectronic systems and considering the results of this work, the authors conclude that a powerelectronicsspecific circuit simulator offers the most convenience. This type of program simulates the power and control parts of the circuit very well. In addition, these types of simulators have low execution times, are numerical robust, and are user friendly.