From the figure below, the zener diode should tap the voltage at level of 360V. Unfortunately, it does not work out. The zener diode is having the breakdown voltage at 360V. Is there any problem occur to the circuit? Thank in advance.

 

How much current is going through the zener diode? Current over the rating of the part will cause the voltage to go higher?

You might want to look at something like a TVS diode.

 

May I ask why the DC voltage at probe 1 is 381V? Don't it suppose to be 0.636*384=244V?

 

You have a very large capacitor following the diode bridge. Both the capacitance and load resistance determine the ripple voltage after the diodes. In your situation, the capacitor has enough capacitance to smooth out the ripple almost entirely. Try the simulation with either a smaller capacitance or smaller load resistor (larger load current) and watch the ripple increase.

 

May I ask why the DC voltage at probe 1 is 381V? Don't it suppose to be 0.636*384=244V?

No, that would be the value for an averaging filter. You would get that value with the rectifiers feeding a simple resistor, or possibly with a choke-input smoothing filter under certain conditions, but with a capacitor filter like this you would normally expect to get closer to the peak value.

The waveform into a resistive load does have an average value of about 0.637 times the peak, if we ignore the voltage dropped in the diodes. Looking at this waveform you would see a series of undulations going right down to zero twice every cycle, but the effect of adding a large smoothing capacitor is to fill in the gaps, so that the output never drops very far below the peak value.

 

From the figure below, the zener diode should tap the voltage at level of 360V. Unfortunately, it does not work out. The zener diode is having the breakdown voltage at 360V. Is there any problem occur to the circuit? Thank in advance.

Where is the current limit resistor for the zener?

 

Where is the current limit resistor for the zener?

Yeah, that's the elephant in the room.

 

Where is the current limit resistor for the zener?

The first circuit is wrong. I have attached modified circuit in post #3. I have few more questions.
1.Why is the 1640uF cap can charge although no resistor before it?
2.How can I increase the charging time?
3.How to compute the charging time in this circuit?

 

The first circuit is wrong. I have attached modified circuit in post #3. I have few more questions.
1.Why is the 1640uF cap can charge although no resistor before it?
A cap will charge even without a resistor before it but may have a very high inrush current. Sometimes a low ohm value resistor is placed to limit the amount of charge current during initial charge.
2.How can I increase the charging time?
Install a resistor in series before the capacitor.
3.How to compute the charging time in this circuit?

T=RC where T is in seconds, R is in ohms and C is in Farads.


Exactly what is the end result you are trying to achieve? 360 volts is pretty high to be experimenting with.

 

T=RC where T is in seconds, R is in ohms and C is in Farads.


Exactly what is the end result you are trying to achieve? 360 volts is pretty high to be experimenting with.

The circuit is to hold a constant voltage at 200V. I bet this is the simplest way to do it? For my case, I have no resistor in series with the capacitor, so my charging time is 0?

 

The capacitor will charge very rapidly, limited only by diode resistance and source impedance.
Do you really need to drive a 300 ohm load? If so, what is it?

 

You are looking at 133 Watts at the load. Your best bet would be to use a transformer to reduce the voltage.