Foreword
In recent years, outdoor power (also known as energy storage or mobile) has flourished. In general, off-site power, using solar or market power, fills up the batteries and releases them when they are needed to provide continuous power for the equipment. Accumulation batteries typically use a 24v/48v homeline programme, which requires 220v ac for electrical equipment, and therefore requires the conversion of 24v dc to 220v ac for dc-ac power conversion links. Since the power required for most applications varies from 500 w to 2000 w, the input voltage is 24 v/48 v, and the input side current is large, the choice of a pedestal solution for low-pressure large currents is required. In comparison, it was found that the tractor was suitable for use at the front end of the dc-dc pressurization, while also satisfying electrical isolation and improving the security of the power supply system. In order to further reduce wear and tear, soft switches need to be achieved by adding a capacitor to the dc-dc 400v output side, associating it with a leak in the transformer, achieving a hyphenation, zeroing of currents in circuits, and achieving zvs and zcs efficiency in the dc-dc chain by regulating the original mos of the capacitor and magnetic sensor parameters. The back end uses a full-bridge reverse circuit using spwm to achieve 220v ac output。
Content planning
1. Modular principles and modelling
2. The principle of single-phase bridge reversers and modelling
3. P+pi double-closure control
Four. Double pi closed ring control before current
5. Pilot test
1 the principles of the switcher and the booster
(1) booster transformer
The pullovers and work wave shapes are shown in figure 1. Two switches in the circuit q1 and q2 are attached at both ends of the transformer's primary circle with a central pump, which can have the equivalent of two fully symmetric single-end positive transformers. D1 and d2 are side-stealing diodes, l and c are the output filter senses and filter caps. In the analysis, the following assumptions were made:
A. All power tubes, diodes, are ideal components; b, capacitors, senses are ideal elements; c, output caps are large enough to be considered a voltage source by c0, rl; d, circuit work is stable。
(a) resuscitating transformers
(b) workwaves
Figure 1
The switching process is shown in figure 2。
(a) modulus 1: q1 conductivity, with input voltage added to the upper side of the transformer, with q2 bearing twice the input voltage, with nvin at the upper end of the side of the transformer, and a whole-stream diode d1 conductor, during which the power provides energy to the load
(b) modular 2: q1 and q2 respectively, the current in the whole pipe d1 is gradually reduced and the current in the d2 is gradually increased until the current in the two tubes is equal (ignominating the magnetic current of the transformer), at which point the transformer can be considered to be short-circuited and the two switches are subject to electric voltage and the output power is provided by the output cones
(a) modular 3: q2 conductor, q1 cut-off, input voltage added to the lower extremity of the transformer, q1 receiving twice the input voltage, nvin at the lower side of the transformer, and d2 conductor of the whole current diode, during which time the power provides energy to the load
Modular 4: q2 and q1 breaks, the current in the whole pipe d2 is gradually decreasing and the current in the d1 is increasing until the current in the two tubes is equal (ignominating the voltage transformer's magnetic current), at which point the transformer can be considered to be short-circuited, the two switches are subject to electrical voltage and the output power is provided by the output capacity。
Figure 2 switch-off process
A reference to the calculation method for the parameters of the booster。
(2) resuscitator
The condensation transformer has expanded its work wave shape as shown in figure 3. In order to achieve zero voltage conductivity and zero current cut-off (zvcs) to achieve the efficiency of the converter, new circuits and control methods are required. A new type of zvcs has been proposed to resonate circuits, as shown in figure 3a. The circuit consists of primary mos tubes (q1, q2), a series of lc-strung circuits, an output integrator (d1-d4), an output capacitor (co) and a load (rl). The resonance sense is the secondary leakage of the transformer and cs1, cs2 is the condensed condensation, including the mosfet leak。
(a) resuscitating condensers
(b) workwaves
Figure 3
An analysis of how the circuit works follows. When the circuit works, the frequency of the operation is close to the inherently coordinated frequency of the circuit lc network. There are four working modes of circuits, the equivalent of which are shown in figure 4 (a), (b), (c) and (d), and the wave shape of circuits are shown in figure 3b. In the analysis, the following assumptions were made:
A. All power tubes, diodes, are ideal components; b, capacitation, senses are ideal elements, cs1=cs2=cs; c, output caps are large enough for c0, rl can be viewed as a voltage source. D. The circuit is in a steady state。
Figure 4
Acoustic cs1 of power tube q1 leak source poles was discharged to zero, t0 hours q1 conductor, q1 is zero voltage conductor, transformer primary flow is through electric current i1, transformer magnetic current linear growth, side-drive network resonance and transmission of energy to side. Cs1 voltage is zero and cs2 voltage is at 2vin in this mode。
Q2 also shut down when mod: t1 turns off power tube q1, when magnetic currents of transformers charge q1 and q2 leaks to the contours cs1 and cs2, which are sufficiently large and have a relatively small capacity and a relatively short duration of charge, so that they are considered to be the same size as magnetic currents, linear changes in the electrical voltage of cs1 voltage from zero to 2vin, reduction of cs2 voltage from 2vin to zero, and reverse and bipolar natural conductor of q2. This pattern ends at vcs2=0。
Modular 3: similar to modular 1, q2-0 voltage conductivity, transmission of energy to the side, cs1 voltage level 2vin。
Model 4: similar to model 2。
References to the calculation methods for the parameters of the resonator。
2 modelled on psim-based tuning convulsors
The pwm controller used in this programme is sg3525. The internal structure includes units such as power supply, osc, pwm reconciliation, soft start, and protection, as shown in figure 5。
Figure 5 internal structure of sg 3525 figure
Pin1 and pin2 are inverted and co-inverted quotations for error amplifiers; pin3 is inducing simultaneous signals outside the oscillator; pin4 is inducing the oscillator output; pin5 is inducing the timing of the oscillator; pin6 is inducing the timing of the proscillator; pin8 is inducing the soft start time; pin9 is in compensation for pwm signals; pin10 is inducing the external failure; pin 11 is in output of pwma; pin 12 is in gnd; pin 13 is in vcc; pin 14 is in guiding the pwmb output; pin 15 is inverted source input; and pin 16 is in the output source benchmark。
Vibrationors: a double-door limited voltage compressor whose voltage is taken from the base power source, with an entry limit of vh = 3. 9 v, a low threshold limit of vl = 0. 9 v, a constant internal flow source towards ct charge, a linear increase in end voltage vc, which constitutes the rise of a sawn-tooth wave, when vc = vh is exported in reverse, the recharge process ends, and the lifting time trice = 0. 67 rtct. When the comparator moves, the circuit work, the ct discharge, the vc drops and forms a sawntooth drop, when vc=vl the comparator output reverses, the discharge process ends, the drop time tfall=1. 3rdct completes a work cycle。
A. Modular principles for pulse generation: using the charge/discharge properties of the capacitation, setting a maximum and lower limit comparison value for charge voltage, compared to the comparator, combining the sr trigger to control the time of charge, thus producing a triangle and oscillator pulse。
B. Pwm generation module: designing digital circuits to generate two-way pwm-driven waveforms in combination with working time-series waveform and digital circuit technology。
C. Rotation transformer model
Figure 6 shows the power-grade circuit model for switching circuits and, in order to bring the simulation closer to the actual situation, the original mos tubes combined with the equivalent of 200 pf (this is a mos output convulsion of several hundred pf., usually associated with the parasitic cap on the pcb), which enters and connects to a 20mf cap, which does not affect the imitation results, plus here is intended to bring it closer to the actual situation and avoid design negligence; the transformer uses a four-round transformer (the largest advantage of high-pressure side is the elimination of the original mos concussion peak (but the error is not at the same frequency as the low-pressure side oscilling frequency, leading to a constant high peak in the mos tube, with the subsequent replacement of the transformer, setting the appropriate parameters, with the basic solution, but, since the transformer parameters are not optimized, the true result is not ideal); the greatest advantage of high-pressure side is the elimination of the original mos convulcence rate (which is less difficult to try to achieve the desired effect of the desired the design is therefore designed to take into account the various factors and not to pursue a single parameter indicator. The power circuit model is as follows:
Figure 6. Modified modulator power model
Simulation parameters: dc input: 40~56v; dc output: 320~430v; output power: 1000w。
Harmonisation parameters: electro-37uh, capacitive 220nf。
Figure 7
Fig. 8 leaking power from the front switch and current from the ditch
Figure 9 front switch zvs
Figure 10 diode zcs
Figure 11 output and input power
