Feb. 23, 2010 - What Simulation Speed Do We Need in Power Electronics?

When we built the first prototype of a 10kW Three-Phase AC/DC Vienna Rectifier in 1994 (see Fig. 1), we started with circuit simulations to make sure the new topology would really work. We used PSpice, and simulating one mains period of 20ms took more than 12 hours.

Today you can perform such a simulation within a few seconds. Try it online with GeckoCIRCUITS (click orange rectangle on this page)! Fast numerical simulations speed up the design process and allow performing parameter variations for system optimization. Fig. 2 shows an optimized rectifier system.

 
Fig. 1: 10kW Three-Phase AC/DC converter (Vienna Rectifier) - prototype from 1994. 

 
Fig. 2: 10kW Three-Phase AC/DC converter (Vienna Rectifier) - optimized prototype from 2007. 

Generally speaking, the simulation speed of speed-optimized circuit solvers is proportional to the 3rd order of the number of nodes of the circuit to be simulated.

Once I was told from an industry partner that they would like to simulate 10 seconds of the starting phase of an electrical motor within one afternoon. Additionally, they would like to simulate transient junction temperatures during this process. With GeckoCIRCUITS you can do this within a couple of minutes depending on your PC hardware - test it online (GeckoCIRCUITS menu File >> Open >> dq_control_pmsm_comment)

 
Fig. 3: Simulate a 10s start-up of a drive in GeckoCIRCUITS within 15 minutes. 

For simulating converters with switching frequencies around 50kHz we typically select a fixed numerical step width between 100ns and 250ns to get reliable results. For EMI related simulations you need less than 20ns numerical time steps width to cover a spectrum up to 30MHz. It can be done easily with GeckoCIRCUITS in less time than one afternoon.