CN110417244A - A high-frequency chopper soft-switch voltage regulator circuit - Google Patents

Abstract

The invention discloses a high-frequency chopper soft switch voltage regulation circuit, which comprises an auxiliary chopper voltage regulation circuit, a main chopper voltage regulation circuit, a PWM drive control circuit and an output circuit, the auxiliary chopper voltage regulation circuit and the main The output circuit is connected with the main chopper voltage regulation circuit, the main chopper voltage regulation circuit and the auxiliary chopper voltage regulation circuit are also connected with the PWM driving control circuit, and the main chopper voltage regulation circuit is controlled by the PWM driving control circuit. The on-off of the voltage circuit and the auxiliary chopper voltage regulation circuit, the external input high-voltage direct current is input to the parallel structure of the auxiliary chopper voltage regulation circuit and the main chopper voltage regulation circuit, and the chopper output is connected to the loop load after passing through the output circuit. Under the control of the PWM drive control circuit, the adjustable DC voltage and current are obtained on the output circuit, and the soft switching process of the switching device is realized under the control of the PWM drive control circuit, which reduces the loss of the switching device and improves the safety of the circuit. .

Description

A high-frequency chopper soft-switch voltage regulator circuit

technical field

The invention belongs to the technical field of high-frequency conversion circuits, in particular to a PWM voltage regulating circuit.

Background technique

The chopper circuit is used in a specific power circuit to change a specific direct current into another fixed voltage or adjustable voltage direct current to provide a switching power supply for the circuit.

In power circuits, high-power semiconductor electronic devices are usually used as electronic switches to realize chopping. In high-frequency environments, high-power semiconductor electronic devices are often turned on at high voltages and turned off at high currents, that is to say, in high-frequency environments The switching device is often in a hard switching state.

The hard switching state has the following problems when the specific power circuit is running: First, the high-frequency on-off of the switching device will generate a large instantaneous power consumption in the inductive and capacitive load, and the total power consumption will increase with the switching frequency of the switching device. The excessive instantaneous power consumption will increase the junction temperature of the switching device, and the stability of the switching device will be threatened; secondly, the peak voltage or peak current generated by the high-frequency on-off of the switching device will cause secondary damage to the switching device. Breakdown; Finally, the high-amplitude voltage mutation and current mutation generated by the switching device during high-frequency on-off will also cause serious electromagnetic interference to the circuit and affect the normal operation of the entire circuit.

In order to overcome the problems of hard switching, various zero-voltage switches (ZVS) and zero-current switches (ZCS) have appeared in succession at home and abroad this year.

The ideal zero-current soft turn-off process is that the current drops to zero first, and the voltage rises slowly to the off-state value, so the switching loss in this turn-off process is theoretically close to zero. In an ideal zero-voltage soft turn-on process, the voltage drops to zero first, and then the current slowly rises to the on-state value, so the switching loss in the turn-on process is theoretically approximately zero.

However, no mature and suitable technical solution has been proposed in the prior art on how to apply the above soft switching idea to a specific circuit to realize the soft on and off of the switching device in the chopper circuit.

Contents of the invention

In order to solve the above problems, the object of the present invention is to provide a high-frequency chopper soft switching circuit in which both the turn-on process and the turn-off process of the switching device realize soft switching process.

To achieve the above object, the technical scheme of the present invention is as follows:

The invention provides a high-frequency chopper soft switch voltage regulation circuit, which includes a PWM drive control circuit, a main chopper voltage regulation circuit, an auxiliary chopper voltage regulation circuit and an output circuit.

Under the high-frequency alternating circuit, setting the chopper circuit can convert the high-voltage DC voltage or current output by the network voltage rectification filter into a DC voltage and current with a specified adjustable amplitude. The conversion process is under the condition of a specific control pulse width signal input. Completed under control.

The PWM drive control circuit in this circuit includes a first pulse width modulation unit, a second pulse width modulation unit, and a zero-voltage detector. The zero-voltage logic detection unit includes a zero-voltage detector and a NOT gate. The zero-voltage detector is used to detect Its input terminal voltage, as the input terminal voltage of zero voltage detector is 0V, then its output terminal outputs low level, as the input terminal voltage of zero voltage detector is not 0V, then its output terminal outputs high level; The input terminal of the zero-voltage detector is connected to the collector of the first IGBT tube. When the voltage at the collector of the first IGBT tube is 0V, the output terminal of the zero-voltage detector outputs a logic "0", and the output terminal of the zero-voltage detector Connect the input terminal of the NOT gate, the output terminal of the zero voltage detector is also connected to the first pulse width modulation unit, and the output terminal of the NOT gate is connected to the second pulse width modulation unit; the external PWM signal is also connected to the first pulse width modulation unit at the same time a width modulation unit and a second pulse width modulation unit. Set the zero voltage detector to detect the collector voltage of the first IGBT tube. If the voltage at this point drops to within the allowable 0V of the error, the zero voltage detector outputs logic "0", and further controls the first pulse width modulation unit through the NOT gate and the second pulse width modulation unit switching output.

When the external PWM signal is input at a high level, the second pulse width modulation unit will send out a control signal to control the second IGBT tube to be turned on within a time limit. A pulse width modulation unit starts to output a control signal to control the conduction of the first IGBT until the external PWM signal stops being input. The PWM drive control circuit is used to time-divisionally drive the first pulse width modulation unit and the second pulse width modulation unit to ensure that when the external PWM signal has a high level input, one of the first IGBT tube and the second IGBT tube is turned on.

Further, the first pulse width modulation unit includes a first NOR gate and a first pulse driver, the input terminal of the first NOR gate is connected to the output terminal of the NOR gate and the external PWM signal, and the output terminal of the first NOR gate is connected to The input end of the first pulse driver, the first pulse driver generates a first pulse signal at the output end, and drives and controls the on-off of the first IGBT tube;

The second pulse width modulation unit includes a second NOR gate, a second pulse width detector, a transmission optocoupler and a second pulse driver, and the input terminal of the second NOR gate is connected to the output terminal of the zero voltage detector and the external PWM signal , the output end of the second NOR gate is connected to the input end of the second pulse width detector, the output end of the second pulse width detector is connected to the output end of the transmission optocoupler, and the output end of the transmission optocoupler is connected to the second pulse driver, the second The second pulse driver generates a second pulse signal to drive and control the on-off of the second IGBT tube;

The output terminal of the first NOR gate is also connected to the input terminal of the second NOR gate; thus, it is ensured that only one channel of signals in the first pulse width modulation unit and the second pulse width modulation unit is gated at the same time.

The second pulse width detector is used to detect the signal width at its input terminal. If the signal width at the input terminal of the second pulse width detector is narrower than the set width, the signal is allowed to be output through its output terminal, otherwise the output is not allowed. Further, the PWM drive control circuit also includes a first optocoupler, the input end of the first optocoupler is connected to the external PWM signal, and the output end of the first optocoupler is simultaneously connected to the first pulse width modulation unit and the second PWM unit. In order to isolate the external PWM signal from the high-frequency environment and prevent the PWM signal input into the circuit from being polluted, a first optocoupler is installed in the PWM drive control circuit to obtain relatively pure PWM input from the source. Of course, after the first optocoupler is set, the phase of the external PWM signal is reversed after passing through the first optocoupler.

Further, the PWM drive control circuit also includes an overcurrent detector and a second optocoupler, the detection terminal of the overcurrent detector is connected to the collector of the first IGBT tube, and the output terminal of the overcurrent detector is connected to the second optocoupler The input terminal of the second optocoupler is connected to the external control center; the overcurrent detector detects the overcurrent at the collector terminal of the first IGBT tube and reports the overcurrent information to the external control center. Large voltage is often accompanied by high current. Connect the detection terminal of the overcurrent detector to the collector of the first IGBT tube. If the detection terminal detects a large current in the collector of the first IGBT tube, it means that the first IGBT tube is working abnormally. , there is a possibility that it has been damaged, at this time the overcurrent detector outputs a logic judgment signal to the external control center, which facilitates the external control center to shut down the circuit in time, prevents further damage to the circuit and facilitates replacement.

Further, the PWM drive control circuit delays the switch, delays the input terminal of the switch and the external PWM signal, and when the external PWM signal is at a high level, the delay switch delays turning on the overcurrent detector for overcurrent logic detection of the collector terminal of the first IGBT tube. Since the turn-on and turn-off of the IGBT tube takes time, if the collector current of the first IGBT tube is directly measured at the moment when the first pulse width modulation unit outputs the turn-on signal, the first IGBT tube will be in a high current state. Such test results would leave no doubt. In this application, a delay switch is set. After the external high-level signal is input to a high level, the delay switch is delayed for an appropriate time. The first IGBT tube should have completed the action in this event, and the collector current of the first IGBT tube is measured after the delay. At this time If the collector of the first IGBT tube is still in a high current state, it is considered that the first IGBT tube must have a fault, and this information will be fed back to the external control center, which is convenient for the external control center to analyze the fault of the system and further shut down the control.

The main chopper voltage regulating circuit in this circuit includes a first diode and a first IGBT tube, the cathode of the first diode is connected to the positive pole of the input high-voltage direct current, and the anode of the first diode is connected to the first IGBT tube The collector, the gate of the first IGBT tube are connected to the PWM drive control circuit, and the emitter of the first IGBT tube is connected to the negative pole of the external input high-voltage direct current.

Further, the main chopper voltage regulating circuit also includes a first capacitor, one end of the first capacitor is connected to the collector of the first IGBT tube and the common end of the first diode, and the other end of the first capacitor is connected to the first IGBT The common end of the emitter of the tube and the negative pole of the external input high voltage.

The auxiliary chopper voltage regulating circuit in this circuit includes a second IGBT tube, a second diode, a third diode, a second capacitor and a first inductance; the cathode of the third diode is connected to the external input high-voltage direct current Anode, the anode of the third diode is connected to the cathode of the second diode, the anode of the second diode is connected to the collector of the second IGBT tube, the emitter of the second IGBT tube is connected to the negative pole of the external input high-voltage direct current, the first One end of an inductor is connected to the common end of the collector of the second IGBT tube and the anode of the second diode, and the other end of the first inductor is connected to the common end of the anode of the first diode and the collector of the first IGBT tube, One end of the second capacitor is connected to the common end of the third diode and the common end of the second diode, and the other end of the second capacitor is connected to the common end of the first inductor, the first diode, and the first IGBT tube.

The output circuit in this circuit includes a second inductance, a third capacitor and a loop load. One end of the second inductance is externally input with the positive pole of high-voltage direct current, and the other end of the second inductance is connected to the anode of the first diode and the first IGBT tube. The common terminal of the collector is connected, and the loop load is connected in parallel with the third capacitor.

The advantage of the present invention is that: using the high-frequency chopping soft-switching voltage regulating circuit provided by the present invention, the above-mentioned circuit can obtain an adjustable direct current with a specified amplitude range on the output circuit under the control of the PWM drive control circuit. When the pulse in the PWM drive control circuit changes, the soft switching process of the switching device is realized, the loss of the switching device is reduced, and the safety of the circuit is improved.

Description of drawings

Fig. 1 is a diagram of the overall circuit structure of the voltage regulation circuit combined with the front stage rectification circuit and filter circuit realized in the specific embodiment of the present invention.

Fig. 2 is a partially enlarged view of part A in Fig. 1 .

Fig. 3 is a partially enlarged view of part B in Fig. 1 .

Fig. 4 is a waveform diagram of a circuit implemented in a specific embodiment of the present invention. Among them, a is the input waveform diagram of the PWM drive control circuit, b is the output waveform diagram of the second pulse driver in the PWM drive control circuit, c is the output waveform diagram of the first pulse driver in the PWM drive control circuit, and d is the first IGBT The change curve of voltage and current on the tube, e is the change curve of voltage and current on the second IGBT tube.

FIG. 5 is a schematic circuit diagram of a high-frequency chopping and voltage regulating circuit implemented in a low-power environment according to a specific embodiment.

FIG. 6 is a schematic circuit diagram of a high-frequency chopping and voltage regulating circuit in a high-power environment realized in the second embodiment.

Fig. 7 is a schematic circuit diagram of a high-frequency chopping and voltage regulating circuit in an ultra-high power environment realized by three specific embodiments.

Detailed ways

In order to make the object, technical solution and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

To achieve the above object, the technical scheme of the present invention is as follows:

When this circuit is working, its circuit structure is shown in Figure 1-3.

The invention provides a high-frequency chopper soft switch voltage regulation circuit, which includes an auxiliary chopper voltage regulation circuit, a main chopper voltage regulation circuit and an output circuit.

Further, the first pulse width modulation unit includes a first NOR gate and a first pulse driver, the input terminal of the first NOR gate is connected to the output terminal of the zero voltage detector and the external PWM signal, and the output of the first NOR gate The terminal is connected to the first pulse driver, and the first pulse driver generates a first pulse signal to drive and control the on-off of the first IGBT tube;

The second pulse width modulation unit includes a second NOR gate, a second pulse width detector, a transmission optocoupler and a second pulse driver, and the input end of the second NOR gate is connected to the output end of the zero voltage detector and External PWM signal, the output end of the second NOR gate is connected to the input end of the second pulse width detector, the output end of the second pulse width detector is connected to the output end of the transmission optocoupler, and the output end of the transmission optocoupler The output end is connected to a second pulse driver, and the second pulse driver generates a second pulse signal to drive and control the on-off of the second IGBT transistor IGBT2.

The PWM drive control circuit also includes a first optocoupler, the input end of the first optocoupler is connected to the external PWM signal, and the output end of the first optocoupler is simultaneously connected to the first pulse width modulation unit and the second pulse width modulation unit. unit. In order to isolate the external PWM signal from the high-frequency environment and prevent the PWM signal input into the circuit from being polluted, a first optocoupler is installed in the PWM drive control circuit to obtain relatively pure PWM input from the source.

The PWM drive control circuit also includes an overcurrent detector and a second optocoupler, the detection end of the overcurrent detector is connected to the collector of the first IGBT tube IGBT1, and the output terminal of the overcurrent detector is connected to the input of the second optocoupler The output terminal of the second optocoupler is connected to the external control center; the overcurrent detector detects that there is an overcurrent between the collector terminal and the emitter terminal of the first IGBT tube IGBT1, and then reports the overcurrent information to the external control center . Large voltage is often accompanied by high current. Connect the detection terminal of the overcurrent detector to the collector of the first IGBT tube IGBT1. If the detection terminal detects a large current in the collector of the first IGBT tube IGBT1, it means that the first IGBT tube IGBT1 is working abnormally and may be damaged. At this time, the overcurrent detector outputs a logic judgment signal to immediately stop the external PWM signal input and send it to the external control center to facilitate the external control center to shut down the circuit or further operation in time to prevent the circuit from further damaged.

PWM drive control circuit delay switch, the input end of the delay switch and the external PWM signal, when the external PWM signal is high level, the delay switch delays the opening of the overcurrent detector to detect the overcurrent logic of the collector terminal of the first IGBT tube IGBT1, and set the delay switch. The purpose is that after the external PWM signal appears, there is a delay in the on-off of the first IGBT tube IGBT1 and the second IGBT tube IGBT2, and the circuit should wait for the first IGBT tube IGBT1 and the second IGBT tube IGBT2 to be completely switched on before detecting their overcurrent. logic.

The main chopper voltage regulating circuit includes a first diode D1 and a first IGBT tube IGBT1, the cathode of the first diode D1 is connected to the positive pole of the external high-voltage direct current, and the cathode of the first diode D1 is connected to the first IGBT tube IGBT1 The collector of the first IGBT tube IGBT1 is connected to the PWM drive control circuit, and the emitter of the first IGBT tube IGBT1 is connected to the negative pole of an external designated high-voltage direct current.

The main chopper voltage regulating circuit also includes a first capacitor C3, one end of the first capacitor C3 is connected to the common end of the first IGBT tube IGBT1 and the first diode D1, and the other end of the first capacitor C3 is connected to the first IGBT tube The common terminal of IGBT1 and the negative pole of the external specified amplitude high-voltage direct current.

The auxiliary chopper voltage regulating circuit includes a second IGBT tube IGBT2, a second diode D2, a third diode D3, a second capacitor C2 and a first inductor L2; the cathode of the third diode D3 is connected to an external specified The anode of the amplitude high-voltage direct current, the anode of the third diode D3 is connected to the cathode of the second diode D2, the anode of the second diode D2 is connected to the collector of the second IGBT tube IGBT2, and the emitter of the second IGBT tube IGBT2 One end of the first inductance L2 is connected to the common end of the first IGBT tube IGBT1 and the first diode D1, and the other end of the first inductance L2 is connected to the second diode D2 and the first diode D1. The common end of the two IGBT tubes IGBT2, one end of the second capacitor C2 is connected to the common end of the third diode D3 and the second diode D2, and the other end of the second capacitor C2 is connected to the first inductor L2 and the first diode Common terminal of D1.

The output circuit includes a loop load RL, a second inductance L1 and a third capacitor C1. One end of the second inductance L1 is connected to the positive pole of the external high-voltage direct current, and the other end of the second inductance L1 is connected to the first diode D1 and the first IGBT tube. The common end of IGBT1 is connected, one end of the third capacitor C1 is connected to the common end of the second inductor L1 and the positive pole of the external high-voltage direct current, the other end of the third capacitor C1 is connected to the common end of the second inductor L1 and the first IGBT tube IGBT1, and the loop The load RL is connected in parallel with the third inductor C1.

After the external 380V three-phase alternating current is input, it becomes about 530V non-adjustable DC voltage through rectification circuit and filter capacitor. After the 530V non-adjustable DC voltage is input into this circuit, it will generate 0~530V on the output circuit. A DC voltage with adjustable amplitude is supplied to the load.

After the external PWM signal is input to the PWM drive control circuit, P1 will be output from the first pulse driver, or P2 will be output from the second pulse driver. The waveforms of the external PWM signal, P1 and P2 are shown in Figure 4.

The external PWM signal starts to be input to the circuit. During the period from 0 to T1, the external PWM signal is input at a low level. During this period, the first pulse driver and the second pulse driver have no pulse width signal output, and the first IGBT tube IGBT1 and The current flowing through the second IGBT tube IGBT2 is all zero. At this time, the energy previously stored in the second inductor flows through the loop load and the first diode D1 to form a loop. Therefore, the current on the loop load as the loop load is provided by the inductor during the time period from 0 to T1. At the same time, since the first IGBT IGBT1 and the second IGBT IGBT2 are both in the cut-off state at this time, the collector of the first IGBT IGBT1 and the collector of the second IGBT IGBT2 remain stable during this time. high voltage.

At time T1, the external PWM signal is reversed, and a high level is input to the circuit. At this time, the PWM drive control circuit will keep the first pulse driver stationary and output a high level from the second pulse driver. At this time, the second IGBT tube IGBT2 is controlled At this time, the current flows through the first inductor L2, and the current at the collector of the second IGBT tube IGBT2 starts to climb slowly from the time T1 due to the characteristic of the inductor itself that hinders the change of the current. At the moment when the second IGBT tube IGBT2 is controlled to be turned on at T1, the voltage between its collector and emitter drops rapidly to 0V under the control of the driving pulse, so at T1, the second IGBT tube achieves almost zero current conduction (ZCS).

In the process of T1～T2, P2 keeps outputting, and the second IGBT tube IGBT2 keeps turning on. During this time, due to the blocking effect of the first inductance L2 on the current, the current at the collector of the second IGBT tube IGBT2 (that is, the current at the collector of the second IGBT tube IGBT2 The current of the second IGBT tube IGBT2) rises slowly, and the potential at the collector of the first IGBT tube IGBT1 drops, which causes the voltage at the collector of the first IGBT tube IGBT1 to drop slowly during T1~T2, and drops to 0V.

At time T2, the PWM drive control circuit controls the first pulse driver to stop the output. At this time, the voltage of the first IGBT tube is 0V, and the zero voltage detector detects that the terminal voltage between the collector and emitter of the first IGBT tube IGBT1 is 0V. , at this time the logic level is 0, input to the input terminal of the second NOT gate, forcing the second pulse driver to become 0V. The pulse driver starts to output P1, and the first IGBT tube IGBT1 is turned on, so at the time T2, the first IGBT tube IGBT1 realizes nearly zero voltage (ZVS) conduction. Since the second pulse driver stops output at this time, the second IGBT tube IGBT2 starts to turn off, and the current flowing through the first inductor will show a decreasing trend at this time, so the first inductor L2 will be due to the resistance of the inductance to the current change Discharging the second capacitor C2 and the second diode D2, the current on the second IGBT tube IGBT2 decreases rapidly, and drops to 0A at time T3, while the current of the second inductor L1 gradually decreases, due to the first The inductor L2 discharges the second capacitor C2, and the voltage on the second capacitor C2 changes. The second capacitor C2 will slowly increase the voltage between the collector and the emitter of the second IGBT tube IGBT2 due to the hindrance effect of the capacitor on the voltage conversion. , but due to the clamping effect of the third diode D3 at the same time, the voltage of the second IGBT tube IGBT2 cannot rise infinitely, and the voltage across the second capacitor C2 is also clamped to the DC voltage value of the input, which is the first IGBT In preparation for the zero-voltage turn-off of the tube IGBT1, the collector voltage of the second IGBT tube IGBT2 remains stable only when it reaches the same amplitude as the external 530V DC voltage, so the second IGBT tube IGBT2 also realizes the Near zero voltage shutdown (ZVS), during which the second capacitor C2 is gradually fully charged.

In the process of T2~T4, P1 keeps output, the first IGBT tube IGBT1 keeps on, the LC filter circuit composed of the second inductor L1 and the third capacitor C1 in the output circuit, the input DC voltage is directly output to the input of the LC filter circuit terminal, thereby transferring energy to the load.

At T4, the external PWM signal is reversed, and a low level is input to the circuit. At this time, the first pulse driver and the second pulse driver have no pulse width signal output, and the first IGBT tube IGBT1 is controlled to cut off at T4, and flows through The current of the first IGBT tube IGBT1 drops rapidly and drops to 0A, and the potential at the collector of the first IGBT tube IGBT1 has a sharp upward trend. In order to hinder this trend, the power in the second capacitor starts to discharge, and the first capacitor C2 starts to charge , prevent the voltage rise between the collector and emitter of the first IGBT IGBT1, prevent the voltage of the first IGBT IGBT1 from increasing sharply, and realize the near zero voltage turn-off (ZVS) of the first IGBT IGBT1 at time T4.

Above, the external PWM signal is input into the circuit for a complete cycle, and the first IGBT tube IGBT1 and the second IGBT tube IGBT2 are respectively soft-on and soft-off in this cycle, which reduces the switching loss of the switching device to the greatest extent. While protecting the circuit, improving the safety and stability of the circuit, the circuit loss is reduced to the greatest extent.

In order to realize the application of the above circuit principles in circuits of different power levels, the present invention will provide three different implementations as follows. In the following three different implementations, in order to adapt to the corresponding power application environment, it will mainly focus on its respective main chopper The voltage regulation circuit and the auxiliary chopper voltage regulation circuit are adjusted, while the output circuit and the PWM drive control circuit remain unchanged. Therefore, when describing the specific implementation methods under different power environments, we will mainly focus on the main chopper voltage regulation circuit and the auxiliary chopper circuit. The wave voltage regulation circuit will be described, and other circuits will not be described in detail.

Specific implementation mode one:

Please refer to FIG. 5 , the voltage regulation circuit implemented in this embodiment is suitable for chopper soft switching voltage regulation in a medium and small power environment.

The circuit realized in this specific embodiment includes a main chopper voltage regulation circuit, an auxiliary chopper voltage regulation circuit, an output circuit and a PWM drive control circuit. The auxiliary chopper voltage regulation circuit is connected to the main chopper voltage regulation circuit, the output circuit is connected to the main chopper voltage regulation circuit, and both the main chopper voltage regulation circuit and the auxiliary chopper voltage regulation circuit are also connected to the PWM drive control circuit. The drive control circuit controls the on-off of the main chopping voltage regulating circuit and the auxiliary chopping voltage regulating circuit; the external specified amplitude high-voltage direct current is input to the parallel structure of the auxiliary chopping voltage regulating circuit and the main chopping voltage regulating circuit, and the external load is connected to on the output circuit.

Wherein, in the chopper circuit implemented in this specific embodiment, the auxiliary chopper circuit includes a clamping diode D13, an auxiliary capacitor C12, an auxiliary inductance L12, an auxiliary chopper first IGBT tube IGBT121 and an auxiliary chopper second IGBT tube IGBT122, the cathode of the clamping diode D13 is connected to the positive pole of the external power supply, the anode of the clamping diode D13 is connected to the collector of the first auxiliary chopper IGBT tube IGBT121, and the gate of the first auxiliary chopper IGBT tube IGBT121 is connected to the first auxiliary chopper The emitter of the IGBT tube IGBT121, the emitter of the first auxiliary chopper IGBT tube IGBT121 is also connected to the collector of the second auxiliary chopper IGBT tube IGBT122, and the gate of the second auxiliary chopper IGBT tube IGBT122 is connected to the PWM drive control circuit , the emitter of the auxiliary chopper second IGBT tube IGBT122 is connected to the negative pole of the external power supply.

The main chopping circuit includes the first main chopping IGBT tube IGBT111, the main chopping second IGBT tube IGBT112 and the main chopping capacitor C13, the collector of the main chopping first IGBT tube IGBT111 is connected to the positive pole of the external power supply, and its gate Its emitter is short-circuited, and its emitter is also connected to the collector of the main chopper second IGBT tube IGBT112. The gate of the main chopper second IGBT tube IGBT112 is connected to the PWM drive control circuit, and its emitter is connected to the negative pole of the external power supply. One end of the main chopper capacitor C13 is connected to the collector of the main chopper second IGBT tube IGBT112 , and the other end is connected to the emitter of the main chopper second IGBT tube IGBT112 .

One end of the auxiliary inductor L12 is connected to the collector of the main chopper second IGBT tube IGBT112, the other end is connected to the collector of the auxiliary chopper second IGBT tube IGBT122, and one end of the auxiliary capacitor C12 is connected to the auxiliary inductor L12 and the main chopper second IGBT The common end of the tube IGBT112, and the other end is connected to the common end of the clamping diode D13 and the first auxiliary chopper IGBT tube IGBT121.

In a low-power environment, the main chopper first IGBT tube IGBT111 and the auxiliary chopper first IGBT tube IGBT121 adopt a half-bridge structure. Among them, the gate and collector of the upper bridge arms of the first auxiliary chopper IGBT tube IGBT121 and the second auxiliary chopper IGBT tube IGBT122 are respectively short-circuited, and only the internal diodes are used to replace the first diode and the collector in the original circuit. The second diode facilitates the arrangement and formation of the main chopper circuit and the auxiliary chopper circuit, and minimizes the molding volume of the circuit.

Specific implementation mode two:

Please refer to FIG. 6 , the chopper circuit implemented in this embodiment is suitable for a high-power high-frequency chopper voltage regulation circuit.

The chopper circuit implemented in this specific embodiment includes a main chopper voltage regulation circuit, an auxiliary chopper voltage regulation circuit, an output circuit and a PWM drive control circuit. The auxiliary chopper voltage regulation circuit is connected to the main chopper voltage regulation circuit, the output circuit is connected to the main chopper voltage regulation circuit, and both the main chopper voltage regulation circuit and the auxiliary chopper voltage regulation circuit are also connected to the PWM drive control circuit. The drive control circuit controls the on-off of the main chopping voltage regulating circuit and the auxiliary chopping voltage regulating circuit; the external specified amplitude high-voltage direct current is input to the parallel structure of the auxiliary chopping voltage regulating circuit and the main chopping voltage regulating circuit, and the external load is connected to on the output circuit.

Among them, in this specific embodiment, the auxiliary chopper circuit includes an auxiliary chopper IGBT tube IGBT22, an auxiliary diode D22, a clamping diode D23, an auxiliary capacitor C22 and an auxiliary inductor L22, and the cathode of the clamping diode D23 is connected to the positive pole of the external power supply , the anode of the clamping diode D23 is connected to the cathode of the auxiliary diode D22, the cathode of the auxiliary diode D22 is connected to the collector of the auxiliary chopper IGBT tube IGBT22, the gate of the auxiliary chopper IGBT tube IGBT22 is connected to the PWM drive control circuit, and the auxiliary chopper IGBT tube The emitter of IGBT22 is connected to the negative pole of an external power supply.

The main chopper voltage regulating circuit includes two main chopper modules, and each main chopper module includes a main chopper first IGBT tube IGBT211, a main chopper second IGBT tube IGBT212 and a main chopper capacitor C23, wherein the main chopper The collectors of the first chopping IGBT tube IGBT211 are connected to the positive pole of the external power supply, the gates are short-circuited to the emitter, and the emitters are connected to the collector of the main chopping second IGBT tube IGBT212. The gates of the two IGBT tubes IGBT212 are connected to the PWM drive control module, and the emitters are connected to the negative pole of the external power supply.

The emitters of the first IGBT tube IGBT211 in the two main chopper modules are also connected to lead out the auxiliary chopper connection end.

One end of the auxiliary inductance C22 is connected to the auxiliary chopper connection terminal, the other end is connected to the collector of the auxiliary chopper IGBT tube IGBT22, one end of the auxiliary capacitor C22 is connected to the common point of the auxiliary inductance and the auxiliary chopper connection end, and the other end is connected to the auxiliary diode D22 and The common end of the auxiliary chopper IGBT tube IGBT22.

In a high-power environment, two main chopper modules are set to meet the high-power chopping requirements. At the same time, the grid and emitter of the first IGBT tube IGBT211 of the main chopper in the main chopper module are short-circuited. The tube can be used as a diode to facilitate circuit formation.

Specific implementation mode three:

Please refer to FIG. 7 , this embodiment is applicable to a super-high-power high-frequency chopper voltage-regulating circuit.

The circuit realized in this specific embodiment includes a main chopper voltage regulation circuit, an auxiliary chopper voltage regulation circuit, an output circuit and a PWM drive control circuit. The auxiliary chopper voltage regulation circuit is connected to the main chopper voltage regulation circuit, the output circuit is connected to the main chopper voltage regulation circuit, and both the main chopper voltage regulation circuit and the auxiliary chopper voltage regulation circuit are also connected to the PWM drive control circuit. The drive control circuit controls the on-off of the main chopping voltage regulating circuit and the auxiliary chopping voltage regulating circuit; the external specified amplitude high-voltage direct current is input to the parallel structure of the auxiliary chopping voltage regulating circuit and the main chopping voltage regulating circuit, and the external load is connected to on the output circuit.

In the circuit realized in this specific embodiment, the auxiliary chopper circuit includes several auxiliary chopper modules, and each auxiliary chopper module includes a clamping diode D33, an auxiliary diode D32, an auxiliary inductor L32, an auxiliary capacitor C32 and The auxiliary chopper IGBT tube IGBT32, the cathode of each clamping diode D33 is connected to the positive pole of the external power supply, the anode of the clamping diode D32 is connected to the cathode of the auxiliary diode D32, and the cathode of the auxiliary diode D32 is connected to the collector of the auxiliary chopper IGBT tube IGBT32, The gate of the auxiliary chopper IGBT tube IGBT32 is connected to the PWM drive control circuit, and the emitter of the auxiliary chopper IGBT tube IGBT32 is connected to the negative pole of the external power supply.

One end of each auxiliary capacitor C32 is connected to the collector of the common end of the auxiliary chopper IGBT tube IGBT32 and the auxiliary diode D32, and the other end is connected to one end of the auxiliary inductance C32, and the other end of the auxiliary inductance C32 is connected to the auxiliary chopper IGBT tube The collector of the IGBT32, the common terminal of the auxiliary capacitor C32 and the auxiliary inductor L32 are also connected in sequence and lead out to the main chopper connection end.

The main chopper circuit includes several main chopper modules, and each main chopper module includes a main chopper first IGBT tube IGBT311 and a main chopper second IGBT tube IGBT312, wherein the main chopper first IGBT tube IGBT311 The collectors are all connected to the positive pole of the external power supply, and the gates are all short-circuited to their emitters. It is connected with the PWM drive control module, and its emitters are all connected with the negative pole of the external power supply.

The emitters of the first IGBT tube IGBT311 in each main chopper module are also connected in sequence to lead out the auxiliary chopper connection end.

The main chopping connection is connected to the auxiliary chopping connection.

In an ultra-high power environment, multiple main chopping modules and multiple auxiliary chopping modules can be set to meet the high-power chopping requirements. At the same time, the gate The pole and the emitter are shorted, and the tube can be used as a diode to facilitate circuit formation. Technicians can add or delete the number of main chopper modules and auxiliary chopper modules according to the power requirements of the circuit.

The advantage of the present invention is that: using the high-frequency chopping soft-switching voltage regulating circuit provided by the present invention, the above-mentioned circuit can obtain an adjustable direct current with a specified amplitude range on the output circuit under the control of the PWM drive control circuit. When the pulse in the PWM drive control circuit changes, the soft switching process of the switching device is realized, the loss of the switching device is reduced, and the safety of the circuit is improved.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention. Inside.

Claims (10)

1. a kind of high frequency chopping Sofe Switch regulating circuit, which is characterized in that the circuit includes that voltage regulation circuit of chopping, master is assisted to cut Wave regulating circuit, PWM drive control circuit and output circuit, the auxiliary voltage regulation circuit of chopping and main voltage regulation circuit of chopping connect It connects, the output circuit is connect with main voltage regulation circuit of chopping, and the main voltage regulation circuit of chopping and auxiliary voltage regulation circuit of chopping are also equal It is connect with PWM drive control circuit, by the main voltage regulation circuit of chopping of PWM drive control circuit and assists voltage regulation circuit of chopping On-off；External input high voltage direct current inputs the parallel-connection structure of auxiliary voltage regulation circuit of chopping and main voltage regulation circuit of chopping, copped wave Output obtains adjustable output voltage by being connected in circuit load after output circuit in circuit load.

2. high frequency chopping Sofe Switch regulating circuit as described in claim 1, which is characterized in that the main voltage regulation circuit of chopping packet First diode and the first IGBT pipe have been included, the cathode of the first diode connects the anode of external input high voltage direct current, The anode of the first diode connects the collector of the first IGBT pipe, the grid connection PWM driving control of the first IGBT pipe Circuit processed, the cathode of the emitter connection input high voltage direct current of the first IGBT pipe.

3. high frequency chopping Sofe Switch regulating circuit as claimed in claim 2, which is characterized in that the main voltage regulation circuit of chopping is also It include first capacitor, one end of the first capacitor is connected to the first IGBT pipe and the common end of first diode, and described the The other end of one capacitor connects the emitter of the first IGBT pipe and the common end of external input high voltage direct current cathode.

4. high frequency chopping Sofe Switch regulating circuit as claimed in claim 3, which is characterized in that the auxiliary voltage regulation circuit of chopping It include the 2nd IGBT pipe, the second diode, third diode, the second capacitor and the first inductance；The yin of the third diode Pole connects the anode of external input high voltage direct current, and the anode of the third diode connects the cathode of the second diode, institute The anode for stating the second diode connects the 2nd IGBT pipe collector, and the emitter of the 2nd IGBT pipe connects external input high pressure The grid of the cathode of direct current, the 2nd IGBT pipe connects PWM drive control circuit；One end connection the of first inductance The other end of the common end of the anode of the collector and the second diode of two IGBT pipes, first inductance connects first diode Anode and the first IGBT pipe collector common end, one end connection third diode and the two or two pole of second capacitor The other end of the common end of the common end of pipe, second capacitor connects the first inductance, first diode and the first IGBT pipe Common end.

5. high frequency chopping Sofe Switch regulating circuit as claimed in claim 4, which is characterized in that the output circuit includes Two inductance, third capacitor and loop load, the anode of one end connection external input high voltage direct current of second inductance, institute State one end of the other end connection third capacitor of the second inductance, the anode of the other end connection first diode of the third capacitor With the common end of the collector of the first IGBT pipe, the loop load is in parallel with third capacitor.

6. high frequency chopping Sofe Switch regulating circuit as claimed in claim 5, which is characterized in that the PWM drive control circuit packet The first pwm unit, the second pwm unit and zero-pressure detector are included, the zero-pressure logic detection unit includes Zero-pressure detector and NOT gate, the zero-pressure detector is for detecting its input terminal voltage, such as the input terminal voltage of zero-pressure detector For 0V, then its output end exports low level, and if the input terminal voltage of zero-pressure detector is not 0V, then the output of its output end is high electric It is flat；The input terminal of the zero-pressure detector connects the collector of the first IGBT pipe, electricity at the collector of the first IGBT pipe Pressure causes the output end of zero-pressure detector to export logical zero when being 0V, the output end of the zero-pressure detector connects the defeated of NOT gate Enter end, the output end of the zero-pressure detector is also connected to the first pwm unit simultaneously, the output end connection of NOT gate the Two pwm units；External PWM signal also accesses the first pwm unit and the second pwm unit simultaneously.

7. high frequency chopping Sofe Switch regulating circuit as claimed in claim 6, which is characterized in that the first pwm unit packet The first nor gate and the first pulse driver, the output end of the input terminal connection NOT gate of first nor gate and outside are included Pwm signal, the output end of first nor gate connect the input terminal of the first pulse driver, and first pulse driver exists Output end generates the first pulse signal, the on-off of the first IGBT pipe of drive control；

Second pwm unit includes that the second nor gate, the second pulse-width detector, transmission optocoupler and the second pulse are driven Dynamic device, the output end and external PWM signal of the input terminal connection zero-pressure detector of second nor gate, second nor gate Output end connect the second pulse-width detector input terminal, second pulse-width detector output end connection transmission optocoupler it is defeated Outlet, the output end of the transmission optocoupler connect the second pulse driver, and second pulse driver generates the second pulse letter Number, the on-off of the 2nd IGBT pipe of drive control；

The output end of first nor gate is also connect with the input terminal of the second nor gate；

Second pulse-width detector is used to detect the signal width of its input terminal, such as signal of the second pulse-width detector input terminal Width is narrower than setting width, then the signal is allowed to export by its output end, does not otherwise allow to export.

8. high frequency chopping Sofe Switch regulating circuit as claimed in claim 7, which is characterized in that the PWM drive control circuit It further include having the first photo-coupler, the input terminal of first photo-coupler is connect with external PWM signal, first optical coupling The output end of device accesses the first pwm unit and the second pwm unit simultaneously.

9. high frequency chopping Sofe Switch regulating circuit as claimed in claim 8, which is characterized in that the PWM drive control circuit It further include having over-current detector and the second photo-coupler, the test side of the over-current detector connects the current collection of the first IGBT pipe Pole, the output end of the over-current detector are connect with the input terminal of the second photo-coupler, the output end of second photo-coupler Connect external control centre；

The over-current detector is used to detect the current amplitude of its input terminal, as the current amplitude of over-current detector input terminal is higher than Its setting electric current amplitude, then its output end exports alarm signal, and otherwise over-current detector does not export；

Second pulse-width detector is also connected with over-current detector, and the signal width of such as input terminal of the second pulse-width detector is wider than Width is set, then the output end for triggering over-current detector issues alarm signal.

10. high frequency chopping Sofe Switch regulating circuit as claimed in claim 9, which is characterized in that the PWM drive control circuit Delay switch, the input terminal and external PWM signal of the delay switch, delay switching delay is opened when external PWM signal high level Open over-current detector.