KR100412734B1 - Modeling method of pulse width modulation device - Google Patents

Abstract

The PWM device is modeled for operation in Semi Automatic Business Environment Research (SABER) simulation software, allowing the computer simulation environment to determine the current consumption of the electrical load due to the PWM device.

The present invention is to classify a control signal input to a PWM device and a signal for switching the input power supplied to the electric load receiving the control signal, and apply the frequency signal in the control signal to the Schedule_event () function supported by the Mast Language And, for the duty signal, the process of determining the on / off duty ratio, and the process of measuring the current consumption by measuring the voltage supplied to the electrical load by switching the PWM element through a control signal determined by the frequency signal and the duty signal It is characterized by including.

Description

MODELING METHOD OF PULSE WIDTH MODULATION DEVICE

The present invention relates to a pulse width modulation (PWM) device. More specifically, the PWM device may be operated in a SABER (Semi Automatic Business Environment Research) simulation software. The present invention relates to a method for modeling a P.M element that can be modeled to enable the computer simulation environment to check the current consumption of an electrical load due to a PWM element.

In general, a PWM device is a switching device that is connected to a specific electric load, for example, a front end or a rear end of a motor to adjust a voltage applied to the electric load. As shown in FIG. 1, a frequency input as a control signal to a PWM device The input voltage is controlled by the duty cycle to form an output voltage. When the control signal is '1', the switch is turned on. When the control signal is '0', the switch is turned off.

Therefore, when an electric load motor is connected to the output terminal of the PWM device, the output of the motor is controlled by the frequency and duty cycle inputted as a control signal to the PWM device.

The conventional method of detecting the current consumption of the electric load through the PWM device for adjusting the voltage applied to the electric load as described above is to connect the PWM device produced as a prototype through development directly to the corresponding electric load and then frequency and duty By applying a control signal consisting of cycles, the current consumption of the corresponding PWM element is measured from the relationship between the input voltage and the output voltage, and from this the current consumption of the corresponding electrical load is measured.

As described above, the method of measuring the current consumption of an electrical load connected to a PWM device at the front end measures a current consumption by implementing a PWM device and a real product of the corresponding electrical load in a circuit, and therefore, it takes a long time to measure the actual current consumption. In addition, the development of a PWM device suitable for an electric load also takes a lot of time and causes a problem that leads to an increase in development costs.

The present invention has been invented to solve the above problems, the object of which is to model the PWM device to be operated by the SABER simulation software to measure the current consumption of the PWM device in the computer simulation environment and thus the current consumption of the electrical load I would have to.

In addition, the modeling of the PWM device is intended to provide convenience, reliability, and development cost reduction in the development of a PWM device having a current consumption suitable for each electric load.

1 is a conceptual diagram of a general PWM device.

2 is a flow diagram of one embodiment for modeling a PWM device in accordance with the present invention.

3 is a simulation circuit diagram for measuring the voltage applied to the PWM device through the modeling of the PWM device according to the present invention.

4 is a graph of simulation results measured through FIG. 3.

5 is a simulation circuit diagram of another embodiment for measuring the voltage passing through the PWM device through the modeling of the PWM device according to the present invention.

6 is a graph of simulation results measured through FIG. 5.

The present invention for realizing the above object comprises the steps of separating the control signal input to the PWM device and the signal for switching the input power supplied to the electrical load receiving the control signal; Applying a frequency signal to a Schedule_event () function supported by Mast Language among the control signals, and determining an on / off duty ratio for the duty signal; And switching a PWM device through a control signal determined by the frequency signal and the duty signal to measure a voltage supplied to an electric load to measure a current consumption amount.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the modeling of the PWM device using SABER's Mast Language is modeled by dividing the control signal generation portion and the switching portion of the power used for the electric load in response to the control signal (S110).

The generating part of the control signal receives the frequency and duty ratio as its input value and outputs the control signal as a clock signal. The clock signal is used as a switching signal as a kind of on / off signal, which will be described later. At the point of generating, note that how to obtain the accurate result by simulating the frequency value more than 1Hz.

In general, when performing simulation, the time step is mainly given as '1'. If you want to simulate with a frequency value of 1Hz or more, the time step should be given as '1' or less than the frequency, so the simulation time becomes longer. .

Therefore, to accurately model this, the Schedule_event () function supported by Mast Language is used (S120).

The general usage of the Schedule_event () function is in the form of Schedule_event (time, statevariable, expression), which means that 'simulation is performed. execute by assigning the value of expression).

Therefore, this Schedule_event () function can be used to accurately control the switch on / off regardless of the time step of the simulation.

In addition, since the duty ratio is to be adjusted in the part of the control signal, for example, when the duty ratio is 30%, the on portion is 30% of the total frequency and the off portion is 70% of the total frequency. It makes sense.

Therefore, since the ON is a section multiplied by the duty ratio for the entire period and the OFF is a section obtained by subtracting the section that is turned on in the entire cycle, the duty ratio is determined through this (S130).

As described above, SABER's Mast Language algorithm for determining the frequency and duty ratio in the control signal portion is set as follows.

element template ctrlgen clock = freq, duty, td, v1, v2, restart

state logic_4 clock

number freq = 0, # Clock frequency.

duty = 0.5, # Clock duty cycle (time pulsed / period)

td = 0 # Initial delay.

enum {l4_0, l4_1, # obsolete specification of logic 0 and 1

_0, _1} v1 = _0, # "Off" state.

v2 = _1 # "On" state.

enum {init, continue} restart = init # An option to eliminate the

# Initial event on clock.

# If restart = init, the clock

# is initialized. An

# event on clock occurs at the

# beginning.

# If restart = continue, the event on

# clock is the event left from

# the previous transient analysis.

# if trip is not specified,

# the clock starts from v0

{

state logic_4 off, # Off state.

on # On state.

state nu tick = 0, # Internal wake-up state.

handle [2], hclk [2], reset = 0

number ton = 0, # Clock on time.

toff = 0 # Clock off time.

# +++++++++++++++++++++++++++++++++++++++++++++++++ +++++

parameters {

# Input parameter checking.

if (td <0)

saber_message ("TMPL_S_EQUIV_POSEQ", instance (), "td")

if (freq <0)

saber_message ("TMPL_S_EQUIV_POSEQ", instance (), "freq")

if ((duty <0) | (duty> 1))

saber_message ("TMPL_S_RANGE", instance (), duty "," 0 ", quot; 1")

# Calculate off and on times.

if (freq> 0) {

ton = duty / freq

toff = 1 / freq-ton

}

}

# +++++++++++++++++++++++++++++++++++++++++++++++++ ++++++

when (dc_init | time_init) {

if ((v1 == l4_0) | (v1 == _ 0)) off = l4_0

else off = l4_1

if ((v2 == l4_0) | (v2 == _ 0)) on = l4_0

else on = l4_1

# time_init may be true without a dc operation (i.e. with trip zero)

hclk = schedule_event (time, clock, off)

# if (freq == 0 time_init) {

# # with freq = 0, the output may change its state once.

# handle = schedule_event (time + td, clock, on)

#}

# set a mark indicating that the events in the event queue

# have been canceled

reset = 1

}

when (tr_start freq == 0) {

# In this case, the initial value of the output state is off and

# change to on in td. It stays on after td.

hclk = schedule_event (time, clock, off)

handle = schedule_event (time + td, clock, on)

}

when (tr_start freq> 0) {

# Start clock ticking after delay time.

# In the case that tr re-starts, since there has been an event

# in the event queue, no event need to be scheduled at this moment.

if (restart == init) {

# tr may start after an alter without dc analysis

if ((v1 == l4_0) | (v1 == _ 0)) off = l4_0

else off = l4_1

if ((v2 == l4_0) | (v2 == _ 0)) on = l4_0

else on = l4_1

# The event on tick remained in the event queue should

# be removed. Otherwise, there may be a redundunt event

# on tick if the previous end point is used as the start

# point of the present tr analysis.

deschedule (hclk)

deschedule (handle)

hclk = schedule_event (time, clock, off)

handle = schedule_event (time + td, tick, 1-tick)

}

else if (reset == 1) {

# in the case the restart = continue, there may have

# two situations:

# 1. trip has been specified. in this case, the event

# in the trip file exists, no need to initial any events;

# 2. trip has not been specified, i.e. start tr without trip

# option and reset is set to 1, in this case,

# the initial event on tick is needed.

handle = schedule_event (time + td, tick, 1-tick)

}

# reset the mark

reset = 0

}

when (event_on (tick)) {

if (clock == off) {

# Turn clock on

if (ton> 0) {

hclk = schedule_event (time, clock, on)

handle = schedule_event (time + ton, tick, 1-tick)

}

}

else {

# Turn clock off

if (toff> 0) {

hclk = schedule_event (time, clock, off)

handle = schedule_event (time + toff, tick, 1-tick)

}

In addition, the switch part controls the input power of the electric load by using the signal from the control signal. When the control signal is converted from '0' to '1', it means to turn on the switch. The PWM input voltage is transferred to the electric load as it is, and when the control signal is changed from '1' to '0', it means to switch off. Therefore, the resistance value is 1MΩ. (S140).

As described above, SABER's Mast Language algorithm for determining the voltage of the switch portion is set as follows.

template swt ctrl p m

state logic_4 ctrl

electrical p, m

{

val v v

state nu R_sw = 1

state logic_4 old_ctrl = l4_1

when (event_on (ctrl)) {

if (ctrl == l4_0 old_ctrl == l4_1) {# Open

old_ctrl = l4_0 # input filtering

R_sw = 100meg # High impedance

schedule_next_time (time)

}

else if (ctrl == l4_1 old_ctrl == l4_0) {# Closed

old_ctrl = l4_1 # Input filtering

R_sw = 1u # Avoid divide by zero

schedule_next_time (time)

}

}

values {

v = v (p)-v (m)

}

equations {

i (p-> m) + = v / R_sw

}

An operation of verifying the simulation of the PWM device using the modeling method as described above will be described with reference to FIG. 3.

As can be seen in the figure, a 10V constant voltage source, a 1K resistor and a PWM device are connected in series, and then the operating state of the PWM device is checked by measuring the voltage of the signal line SW input to the PWM device.

Thus, for example, when the frequency input to the PWM device as a control signal is 10Hz, and the duty is 30%, the voltage input to the PWM device is detected as shown in FIG. 4, as shown in FIG. Even when a 10V constant voltage power is supplied, the average voltage input to the PWM device drops to 7.07V due to a control signal input at a frequency of 10Hz and a duty of 30%.

This is interpreted as an influence by the switching role of the PWM device.

In another embodiment, an operation of verifying a simulation of a PWM device will be described with reference to FIG. 5.

As can be seen in the figure, a 10V constant voltage source and a PWM device are connected by a wire (r.src) having a 1K resistance value, and a load resistance (r.r1) having a resistance value of 9Ω is connected to the output terminal of the PWM device. After connecting in series, input the control signal of 1Hz frequency and 50% duty to the PWM device and check the operation status of the PWM device by measuring the voltage across the load resistor.

In the above configuration, assuming that the PWM device is not connected, the voltage of 10V supplied is 1V across the wire resistance (r.src) and 9V is applied to the load resistor (r.r1). The power dissipated in the resistor can be thought of as 9W.

However, when the PWM device is connected, as shown in the analysis result of FIG. 6, a voltage of 0.4966 V is applied to the wire resistance (r.src), and a voltage of 9.5033 V is input to the PWM device, but the duty is 50 as a control signal. Since the output voltage is determined as 9.5033V / 2 because it is applied in%, the voltage applied to the load resistance (r.r1) finally becomes 4.47V.

Therefore, the final power consumption is 2.219W, which is significantly reduced compared to the case where no PWM device is connected.

As described above, the present invention can model the PWM device to check the current consumption of the electrical load connected to the output terminal of the PWM device in a computer simulation environment, thereby providing reliability and convenience in determining the control signal signal value of the PWM device.

Claims (3)

Dividing the control signal input to the PWM device and the signal for switching the input power supplied to the electrical load in response to the control signal; Applying a frequency signal to a Schedule_event () function supported by Mast Language among the control signals, and determining an on / off duty ratio for the duty signal; And switching a PWM device through a control signal determined by the frequency signal and the duty signal to measure a voltage supplied to an electrical load to measure a current consumption amount. The method of claim 1, A method of modeling a PW element, characterized in that the on / off of the switch is determined regardless of the simulation time step by applying to the Schedule_event () function. The method of claim 1, The duty ratio is set to the interval multiplied by the duty ratio of the entire period to the ON, and the section subtracting the interval that is turned on in the entire period is set to off WM element modeling method.