How To Create A Transformer Using LTSpice
How to create a transformer using LTSpiceTransformers that are used here simply steps up or down AC voltages.Primary Power Secondary Power๐๐ ๐ผ๐ cos (๐) ๐๐ ๐ผ๐ cos (๐)๐๐ ๐๐ ๐ผ๐ ๐๐ ๐๐ ๐ผ๐The relation between turn ratio and inductor ratio can be written as;๐๐ ๐๐ ๐ผ๐ ๐ฟ๐ ( )๐๐ ๐๐ ๐ผ๐๐ฟ๐ Example: Find the turn ration of a transformer if primary inductance is 100H and secondaryinductance is 1 H.Using the equation๐๐๐๐ ๐ฟ๐100 ( ๐ฟ ) (๐ 1) 10 .This is a step down transformer.Step down Voltage Transformer Number of primary turns Number of secondary turns Primary voltage Secondary voltageStep up Voltage Transformer Number of primary turns Number of secondary turns Primary voltage Secondary voltageExercise: We will design a step down transformer using LTSpice with 5:1 turn ratio. We canuse Vp 170V, fp 60Hz.
Step 1) You need two inductors. Change inductor names as Lp and Ls. Right click on L1 andchange it to Lp and repeat same process for L2. Step 2) Right click on Lp and L2s to open inductor properties window.Step 3) This is an optional step. We will rotate Ls to get a better look for our transformer.To get this you need to select Ls and rotate 900 and thenmirror it and then rotate it 900 again.This will make sure input and output have same phase.Phase dots are on the same side for both Lp and Ls.To get this you need to select Ls and rotate 180 0.This will make sure input and output have 1800 phasedifference. Phase dots are not on the same side.
Step 3) Now we can connect Vs and RL to our circuit. Make sure Vs has following properties.Make sure you add really small series resistance to source (Rs 0.0001 โฆ). After adding RL 1kโฆload resistance you should have the following circuit.This transformer wonโt work properly because LTSpice does not know this is a transformer. Thislooks like two inductors are in the circuit. We need to tell LTSpice these are transformer. Wewill use a Spice directive to add a K-Statement (โK Lp Ls 1 โ) to this circuit. Click onandadd โK Lp Ls 1 โ. This will tell LTSpice that Lp is primary and Ls is secondary of the transformer.
The last number is called mutual coupling coefficient and can be between 0 and 1. 1 meansperfect coupling (no leakage inductance) between the inductors. During simulations we will use1 for this coefficient. We also need to add transient analysis to see the voltage levels at primaryand secondary. The freqiecny is 60Hz and that means 1 cycle time (period) will be 1/60. If wewant to see 6 cycles we need to have 6/60 0.1 second time for simulation. We will add Spicedirective to our circuit.After this we can simulate and see the Vp and Vs of the transformer.After adding two cursors we can see Vp 169.123V and Vs 33.8016V . This shows that turnratio is 5:1.
Exercise: We will design a step down center tapped transformer using LTSpice with 20:1 turnratio. We can use Vp 170V, fp 60Hz. The center tapped transformer secondary will bedivided into two (Vs1 and Vs2) with same amplitude and 1800 phase difference.This time we will use 3 inductances. The steps are same. Here is the circuit. Please pay attentionto phase dots. This is a full wave rectifier circuit.
will use a Spice directive to add a K-Statement (โK Lp Ls 1 โ) to this circuit. Click on and add โK Lp Ls 1 โ. This will tell LTSpice that Lp is primary and Ls is secondary of the transformer. The last number is called mutual coupling coefficient and can be between 0 and 1. 1 means
3. Instrument transformer: Used in relay and protection purpose in different instruments in industries . . Current transformer (CT) . Potential transformer (PT) . Open circuit and Short circuit Test on transformer . These two transformer tests are performed to find the parameters of equivalent circuit of transformer and losses of the transformer.
Transformer Design & Design Parameters - Ronnie Minhaz, P.Eng. Transformer Consulting Services Inc. Power Transmission Distribution Transformer Consulting Services Inc. Generator Step-Up Auto-transformer Step-down pads transformer transformer 115/10 or 20 kV 500/230 230/13.8 132 345/161 161 161 230/115 132 230 230/132 115 345 69 500 34 GENERATION TRANSMISSION SUB-TRANSMISSION DISTRIBUTION .
Transformer Lab 1. Objectives: 1.1 Comparison of the ideal transformer versus the physical transformer 1.2 Measure some of the circuit parameters of a physical transformer to determine how they affect transformer performance. 1.3 Investigate the ideal transformer and ca
transformer there are hysteresis and eddy current losses in transformer core. Theory of transformer on no-load, and having no winding resistance and no leakage reactance of transformer Let us consider one electrical transformer with only core losses. That means it has only core losses but no copper lose and no leakage reactance of transformer.
Step 13: Now click on the 2-Winding Transformer icon . Place the 2-winding transformer in the same way that you placed the previous two components. Join the primary of the transformer to the Main Bus. Double click the transformer icon and set the following properties: On the Info Tab o Change the transformer ID to "Main Transformer".
the distribution magnetic flux in the transformer. It has been used ANSYS Package Version 11 to model the distribution transformer.Table (1) shows the data of distribution transformer. 3.1 Transformer Geometry (Building and meshing): The transformer study is 250 kVA, three phase distribution core type "stacked core" transformer.
A transformer-based UPS may use a transformer before the rectifier and requires an isolation transformer after the inverter to derive the voltage being delivered to the critical load. Transformer-free UPS designs use power and control electronics technologies to eliminate the need for an isolatio
6. Disconnect all the SCG transformer primary leads. 7. Remove the three remaining screws securing the transformer. Remove the transformer from the enclosure. To install the transformer assembly (see Figure 1 & 2, page 7 & 8): 1. Mount the transformer onto the back panel of the enclosure. Secure the
