CN214281254U - Silicon controlled rectifier drive circuit and frequency converter - Google Patents

Abstract

The utility model discloses a silicon controlled rectifier drive circuit and converter. The multi-path silicon controlled rectifier driving circuit comprises a voltage sampling circuit, a voltage sampling circuit and a voltage sampling circuit, wherein the voltage sampling circuit is connected with the input end of a silicon controlled rectifier rectifying circuit and is used for respectively detecting multiphase alternating current voltages input into the silicon controlled rectifier rectifying circuit and outputting corresponding voltage sampling signals; the main controller is connected with the output ends of the multiple paths of voltage sampling circuits and used for outputting corresponding driving signals according to the voltage sampling signals so as to drive the corresponding silicon controlled rectifiers to work; the first end of the monitoring circuit is connected with the output end of the multi-path voltage sampling circuit, the second end of the monitoring circuit is connected with the output end of the main controller, and the third end of the monitoring circuit is the output end of the silicon controlled rectifier driving circuit; the monitoring circuit is used for adjusting the driving signal output by the main controller according to the voltage sampling signal and outputting the adjusted driving signal to control the on-off of each silicon controlled rectifier in the silicon controlled rectifier circuit. The utility model discloses silicon controlled rectifier drive circuit can drive silicon controlled rectifier circuit in a flexible way and carry out the rectification.

Description

Silicon controlled rectifier drive circuit and frequency converter

Technical Field

The utility model relates to a frequency conversion technology field, in particular to silicon controlled rectifier drive circuit and converter.

Background

At present, a silicon controlled rectifier circuit in a frequency converter has two driving schemes of software and hardware. The software is adopted to directly drive for rectification, and the related software program is not reliable enough or runs away, so that the silicon controlled rectifier in the silicon controlled rectifier circuit cannot be normally driven, and the rectification effect is not reliable enough; the hardware drive is adopted, phase shift angle control cannot be realized, and electronic elements such as an electrifying buffer resistor and the like are required to be used during electrifying, so that not only is the occupied space occupied, but also the system cost is increased. Therefore, whether a software driver or a hardware driver is adopted, the problem that the driver is not flexible enough exists.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a silicon controlled rectifier drive circuit aims at solving the not flexible enough problem of silicon controlled rectifier circuit drive.

In order to achieve the above object, the present invention provides a silicon controlled driving circuit. The silicon controlled rectifier drive circuit is used for driving the silicon controlled rectifier circuit to work, the silicon controlled rectifier circuit comprises at least one silicon controlled rectifier, and the silicon controlled rectifier drive circuit comprises:

the multi-path voltage sampling circuit is connected with the input end of the silicon controlled rectifier circuit and is used for respectively detecting the multiphase alternating current voltage input to the silicon controlled rectifier circuit and outputting corresponding voltage sampling signals;

the main controller is connected with the output ends of the voltage sampling circuits, and is used for outputting a driving signal to drive the corresponding silicon controlled rectifier to work and adjusting the output driving signal according to the voltage sampling signals fed back by the voltage sampling circuits; and

the first end of the monitoring circuit is connected with the output ends of the voltage sampling circuits, the second end of the monitoring circuit is connected with the output end of the main controller, and the third end of the monitoring circuit is the output end of the silicon controlled rectifier driving circuit;

the monitoring circuit is used for adjusting the driving signal output by the main controller according to the voltage sampling signal and outputting the adjusted driving signal to control the on-off of each silicon controlled rectifier in the silicon controlled rectifier circuit.

Optionally, the monitoring circuit includes a multi-way switch control branch and a multi-way switch branch;

the input end of the switch control branch is the first end of the monitoring circuit, the output end of the switch control branch is connected to the control end of the switch branch, the input end of the switch branch is the second end of the monitoring circuit, and the output end of the switch branch is the third end of the monitoring circuit.

Optionally, each of the switch control branches has a first input end for one-to-one connection with the multiple voltage sampling circuits and a second input end for accessing a reference voltage signal;

the switch control branch is configured to output a switch control signal when the voltage sampling signal is equal to the reference voltage signal, so that the switch branch 32 can operate according to the switch control signal.

Optionally, each of the switch control branches includes a voltage comparator, a first resistor, and a second resistor; the reverse end of the voltage comparator is a first input end of the switch control branch circuit, the in-phase end of the voltage comparator is a second input end, the in-phase end of the voltage comparator is also connected with one end of the second resistor through the first resistor, and the other end of the second resistor is used for connecting a threshold voltage; and the output end of the voltage comparator is connected with the common end of the first resistor and the second resistor to form the output end of the switch control branch circuit.

Optionally, the controlled ends of the switch branches are connected with the output ends of the switch control branches in a one-to-one correspondence manner, the input ends of the switch branches are respectively connected with the output end of the main controller, and the output ends of the switch branches are respectively connected with the gate poles of the corresponding thyristors in a one-to-one correspondence manner; each switch branch circuit is used for adjusting the driving signal output by the main controller according to the switch control signal and outputting the adjusted driving signal to control the on-off of each silicon controlled rectifier in the silicon controlled rectifier circuit.

Optionally, the thyristor drive circuit further comprises:

the signal modulation circuit is respectively connected with the output ends of the voltage sampling circuits and the input end of the main controller and is used for outputting the voltage sampling signals to the main controller after operational amplification;

and the power amplification circuit is respectively connected with the output ends of the monitoring circuits and the gate poles of the corresponding silicon controlled rectifiers, and is used for amplifying the power of the driving signals output by the monitoring circuits after adjustment and outputting the driving signals to the gate poles of the corresponding silicon controlled rectifiers.

Optionally, the thyristor drive circuit further comprises: the multi-path voltage detection circuit is used for detecting the voltage between the anode and the cathode of each silicon controlled rectifier in the silicon controlled rectifier rectification circuit and outputting corresponding voltage detection signals to the main controller;

and the main controller is also used for determining the voltage between the anode and the cathode of each controllable silicon according to the voltage detection signal and generating a corresponding driving signal.

The utility model also provides a frequency converter, the frequency converter includes:

the alternating current input end is used for accessing alternating current voltage;

the silicon controlled rectifier circuit comprises at least one silicon controlled rectifier; and

the thyristor drive circuit as described above;

the input end of the silicon controlled rectifier circuit is connected with the alternating current input end, and the controlled end of the silicon controlled rectifier circuit is connected with the output end of the silicon controlled rectifier driving circuit; the silicon controlled rectifier circuit is used for converting the accessed alternating voltage into direct current voltage and outputting the direct current voltage according to the silicon controlled rectifier driving signal output by the silicon controlled rectifier driving circuit.

Optionally, the silicon controlled rectifier circuit is a single-phase bridge rectifier circuit;

or the silicon controlled rectifier circuit is a three-phase bridge type full-control rectifier circuit;

or the silicon controlled rectifier circuit is a three-phase bridge type semi-controlled rectifier circuit.

Optionally, when the thyristor rectification circuit is a three-phase bridge type half-controlled rectification circuit, anodes of the thyristors in the thyristor rectification circuit are connected to the ac input terminal, cathodes of the thyristors are connected to each other through a positive voltage bus, and a ground terminal of the thyristor drive circuit is connected to the positive voltage bus.

Optionally, when the silicon controlled rectifier circuit is a three-phase bridge type half-controlled rectifier circuit; the three-phase bridge type semi-controlled rectifying circuit comprises a first silicon controlled rectifier, a second silicon controlled rectifier, a third silicon controlled rectifier, a first switching tube, a second switching tube and a third switching tube; anodes of the first silicon controlled rectifier, the second silicon controlled rectifier and the third silicon controlled rectifier are respectively connected with cathodes of the first switch tube, the second switch tube and the third switch tube in a one-to-one correspondence manner, cathodes of the first silicon controlled rectifier, the second silicon controlled rectifier and the third silicon controlled rectifier are connected with a positive electrode output end of the silicon controlled rectifier circuit through a positive voltage bus, and anodes of the first switch tube, the second switch tube and the third switch tube are connected with a negative electrode output end of the silicon controlled rectifier circuit through a negative voltage bus; the controlled ends of the first controllable silicon, the second controllable silicon and the third controllable silicon are respectively connected with the output end of the controllable silicon driving circuit; the common ends of the first silicon controlled rectifier and the first switch tube, the second silicon controlled rectifier and the second switch tube, and the third silicon controlled rectifier and the third switch tube are respectively three-phase input ends of the three-phase bridge rectifier circuit.

Optionally, the frequency converter further includes a bus capacitor and an inverter;

one end of the bus capacitor is connected with the positive output end of the silicon controlled rectifier circuit, and the other end of the bus capacitor is connected with the negative output end of the silicon controlled rectifier circuit;

the inverter is connected in parallel with the bus capacitor.

The silicon controlled rectifier driving circuit of the utility model is provided with a multipath voltage sampling circuit, a main controller and a monitoring circuit; the multi-path voltage sampling circuits are used for respectively detecting the multi-phase alternating current voltage input to the silicon controlled rectifier circuit and outputting corresponding voltage sampling signals, so that the main controller can output corresponding driving signals according to the voltage sampling signals to drive the corresponding silicon controlled rectifiers to work, and the monitoring circuits are synchronously connected with the same voltage sampling signals and the same driving signals, so that the monitoring circuits can adjust the driving signals according to the voltage sampling signals to further control the disconnection of the silicon controlled rectifiers. The utility model discloses silicon controlled rectifier drive circuit adopts main control unit output drive signal to drive silicon controlled rectifier circuit and carry out rectification, therefore has the control flexibility of software drive, and the electricity need not to use many advantages such as electricity buffer resistance; and the monitoring circuit of the hardware circuit is arranged to monitor the software drive of the main controller, so that when the software drive program is not reliable enough or the drive signal is abnormal due to runaway, the output of the abnormal drive signal is blocked in time, the reliability of rectification is improved, and the silicon controlled rectifier circuit is flexibly driven to rectify the current.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

Fig. 1 is a schematic diagram of functional modules of an embodiment of the silicon controlled driving circuit of the present invention;

fig. 2 is a schematic diagram of a functional module of another embodiment of the silicon controlled driving circuit of the present invention;

fig. 3 is a schematic circuit diagram of an embodiment of the frequency converter of the present invention;

fig. 4 is a schematic circuit diagram of a switch control branch in an embodiment of the frequency converter of the present invention;

fig. 5 is a schematic diagram of a signal timing sequence of an embodiment of the frequency converter of the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				10	Voltage sampling circuit	S1	First controlled silicon
20	Main controller	S2	The second controlled silicon
				30	Monitoring circuit	S3	Third controlled silicon
31	Switch control branch	T1	First switch tube
				32	Switch branch	T2	Second switch tube
40	Signal modulation circuit	T3	Third switch tube
				50	Power amplifier circuit	R1	A first resistor
60	Voltage detection circuit	R2	Second resistance
				70	AC input terminal	C	Bus capacitor
80	Silicon controlled rectifier circuit	P	Positive voltage bus
				90	Inverter with a voltage regulator	N	Negative voltage bus
U1	Voltage comparator

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In the present application, unless expressly stated or limited otherwise, the terms "connected" and "fixed" are to be construed broadly, e.g., "fixed" may be fixedly connected or detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, descriptions in the present application as to "first", "second", and the like are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicit to the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides a silicon controlled rectifier drive circuit.

Referring to fig. 1 to 5, in an embodiment of the present invention, the silicon controlled rectifier driving circuit is used for driving the silicon controlled rectifier rectifying circuit 80 to work, at least one silicon controlled rectifier is included in the silicon controlled rectifier rectifying circuit 80, the silicon controlled rectifier driving circuit includes:

the multi-path voltage sampling circuit 10 is connected with the input end of the silicon controlled rectifier circuit 80 and is used for respectively detecting the multiphase alternating current voltage input into the silicon controlled rectifier circuit 80 and outputting corresponding voltage sampling signals;

the main controller 20 is connected with the output ends of the multiple voltage sampling circuits 10, and is configured to output a driving signal to drive the corresponding thyristors to operate, and adjust the output driving signal according to the voltage sampling signals fed back by the multiple voltage sampling circuits 10; and

a first end of the monitoring circuit 30 is connected with the output ends of the multiple voltage sampling circuits 10, a second end of the monitoring circuit 30 is connected with the output end of the main controller 20, and a third end of the monitoring circuit 30 is the output end of the thyristor driving circuit;

the monitoring circuit 30 is configured to adjust the driving signal output by the main controller 20 according to the voltage sampling signal, and output the adjusted driving signal to control on/off of each thyristor in the thyristor rectification circuit 80.

In this embodiment, the multi-phase ac voltage connected to the input terminal of the silicon control rectifier circuit may be a three-phase ac voltage of a power grid or a single-phase ac voltage, and the number of phases is at least one phase. Each voltage sampling circuit 10 in the multiple voltage sampling circuits 10 can be constructed by adopting a resistance element or a hall device, or can be realized by adopting a voltage sampling special chip; it is understood that the number of the multiple voltage sampling circuits 10 is set according to actual needs, and is not limited herein. The sampling end of each path of voltage sampling circuit 10 is connected to the one-phase ac voltage input to the thyristor rectification circuit 80, so as to sample the ac voltage and output a corresponding voltage sampling signal.

The main controller 20 may be a microprocessor such as an MCU, a DSP or an FPGA, or may also be implemented by a programmable logic controller PLC, which is not limited herein. A person skilled in the art may integrate some hardware circuits and software programs or algorithms into the main controller 20, and store related data, and may correspondingly connect with a plurality of output terminals of the multi-path voltage sampling circuit 10 and other functional circuits/modules in the thyristor driving circuit through a plurality of interfaces/pins of the main controller 20, so that when the corresponding interfaces/pins of the main controller 20 receive the voltage sampling signal of the ac voltage output by the voltage sampling circuit 10, by operating or executing the software programs and/or algorithms in the main controller 20, and calling the stored data, a corresponding driving signal may be output to the gate of the corresponding thyristor in the thyristor rectifying circuit 80 according to the voltage sampling signal, so as to drive the corresponding thyristor to operate. Wherein, the driving signal can be realized by a PWM control signal. For example, the main controller 20 may be integrated with a PWM generating circuit, and various duty ratio parameters and period parameters are pre-stored, so that the PWM generating circuit may output PWM control signals with various frequencies and phases to the plurality of thyristors in the thyristor rectification circuit 80 according to the multiple single-phase ac voltage sampling signals output by the multiple voltage sampling circuits 10, so as to drive the thyristors to be turned on/off in a corresponding order, thereby performing rectification conversion. In practical application, the main controller 20 can adjust the phase-shift trigger angle, i.e. the conduction angle, in different driving signals through an integrated software program or algorithm to control the driving current of the corresponding thyristor, so as to realize various control effects on the thyristor rectification circuit 80; or, the beneficial effects of various software drivers such as power-on slow start can be realized by presetting control parameters such as power-on delay time and the like.

The monitoring circuit 30 can be implemented by a hardware circuit constructed by a voltage comparator and a logic device, but in other embodiments, it can also be implemented by an integrated control chip. The monitoring circuit 30 has a plurality of first ends connected to the output ends of the multi-path voltage sampling circuit 10 in a one-to-one correspondence manner, and a second end electrically connected to the plurality of output ends of the main controller 20, so as to obtain and acquire the multi-path voltage sampling signals and access the multi-path driving signals, respectively, and determine whether the driving signals output by the main controller 20 are normal by analyzing and judging each of the multi-path voltage sampling signals and the corresponding driving signals. For example, the monitoring circuit 30 may compare the voltage sampling signal of each path with a voltage reference signal to determine whether the front-end circuit is normal, and further determine whether the driving signal output by the main controller 20 is normal when the front-end circuit is determined to be normal, and enable the main controller 20 to normally output the driving signal to the gate of the thyristor when both the front-end circuit and the driving signal are determined to be normal; when one of the front-end circuit or the driving signal is determined to be abnormal, the high level in the driving signal can be adjusted to be the low level, so that each thyristor in the thyristor rectification circuit 80 receives the low level signal, and the thyristor is controlled to stop working (namely, be disconnected); or the voltage sampling signal and the driving signal of each path may be converted into a digital signal by the ADC conversion circuit and then output to the microprocessor, and the microprocessor compares and analyzes the voltage sampling signal and the driving signal converted into the digital signal to determine whether the ac voltage corresponding to the voltage sampling signal is normal and whether the driving signal is abnormal, where the determination mode is determined according to actual needs, and is not limited herein. In practical application, when the monitoring circuit 30 monitors that the front-end power grid fluctuates, each thyristor in the thyristor rectification circuit 80 can be controlled to be switched off, so that the abnormal alternating current cannot be output after being rectified by the thyristor rectification circuit 80; when the front-end power grid is normal, the driving signal output by the main controller 20 can be further monitored according to the normal voltage sampling signal, and when the driving signal is detected to be abnormal, the thyristors are also controlled to be switched off, so that the abnormal driving signal is prevented from influencing the rectification quality. It will be appreciated that the monitoring circuit 30 may also automatically restore the connection of the line after the grid or drive signal has returned to normal.

In an optional embodiment, the multiple detection ends of the multi-path voltage sampling circuit 10 are used to respectively detect the bus voltage of the anode alignment voltage bus of the multiple thyristors in the thyristor rectification circuit 80, that is, the ac voltage of each phase input to the thyristor rectification circuit 80 by the power grid is directly detected, and the rest of the monitoring steps are the same as those in the above embodiment and are not described herein again.

The silicon controlled rectifier driving circuit of the utility model is provided with a multi-path voltage sampling circuit 10, a main controller 20 and a monitoring circuit 30; the multi-path voltage sampling circuit 10 detects the multi-phase alternating current voltage input to the thyristor rectification circuit 80, and outputs corresponding voltage sampling signals, so that the main controller 20 can output corresponding driving signals according to the voltage sampling signals to drive the corresponding thyristors to work, and the monitoring circuit 30 is adopted to synchronously access the same voltage sampling signals and driving signals, so that the monitoring circuit can adjust the driving signals according to the voltage sampling signals, and further control the thyristors to be switched off. The utility model discloses the silicon controlled rectifier drive circuit adopts main control unit output drive signal to drive silicon controlled rectifier circuit 80 to rectify, therefore has the control flexibility of software drive, and the electricity need not to use many advantages such as electricity buffer resistance; and through setting up the monitoring circuit 30 of the hardware circuit, monitor the software drive of the main control unit, in order to when the driving signal is unusual because of the not reliable enough or run away of the software driving program, block the output of the unusual driving signal in time, help to improve the reliability of rectification, thus realize that drives the silicon controlled rectifier circuit 80 to commutate flexibly.

Referring to fig. 1 to 5, in an embodiment of the present invention, the monitoring circuit 30 includes a multi-way switch control branch 31 and a multi-way switch branch 32;

the input end of the switch control branch 31 is the first end of the monitoring circuit 30, the output end of the switch control branch 31 is connected to the control end of the switch branch 32, the input end of the switch branch 32 is the second end of the monitoring circuit 30, and the output end of the switch branch 32 is the third end of the monitoring circuit 30.

In this embodiment, the switch control branch 31 is configured to access a plurality of voltage sampling signals output by the multi-path voltage sampling circuit 10, and perform judgment and analysis on the accessed plurality of voltage sampling signals, so that when the ac voltage corresponding to the plurality of voltage sampling signals is judged to be abnormal, a type of switch control signal that controls the switch branch to adjust the driving signal may be output, so as to disconnect each thyristor; and when the alternating current voltage of the phase corresponding to the plurality of voltage sampling signals is judged to be normal, outputting a second type of switch control signal to enable the second type of switch control signal to work normally. The input ends of the multiple switch branches 32 may be connected to the multiple output ends of the main controller 20 in a one-to-one correspondence, and the multiple output ends of the switch branches 32 are connected to the gates of multiple thyristors in the thyristor rectification circuit in a one-to-one correspondence. By such arrangement, the switch control branch 31 and the switch branch 32 jointly execute the function of the monitoring circuit 30, so as to realize the monitoring of the software drive by the hardware circuit, thereby making up the deficiency of the software drive.

Referring to fig. 1 to 5, in an embodiment of the present invention, each of the switch control branches 31 has a first input end for one-to-one connection with the multiple voltage sampling circuits 10 and a second input end for accessing a reference voltage signal;

the switch control branch 311 is configured to output the switch control signal when the voltage sampling signal is equal to the reference voltage signal, so that the switch branch 32 can operate according to the switch control signal.

Further, each switch control branch comprises a voltage comparator U1, a first resistor R1, and a second resistor R2; the reverse end of the voltage comparator U1 is a first input end of the switch control branch, the in-phase end of the voltage comparator U1 is the second input end, the in-phase end of the voltage comparator U1 is further connected with one end of the second resistor R2 through the first resistor R1, and the other end of the second resistor R2 is used for connecting a threshold voltage; the output terminal of the voltage comparator U1 is connected to the common terminal of the first resistor R1 and the second resistor R2 to serve as the output terminal of the switch control branch 31.

In this embodiment, the number of the multiple switch control branches 311 (in this embodiment, reference numeral 311 represents one switch control branch for explanation) is set to match the number of the voltage sampling signals, and the switch control signal may be a level signal. Each switch control branch 311 is used for accessing and judging a voltage sampling signal, and when the voltage value corresponding to the voltage sampling signal is equal to the voltage value corresponding to the reference voltage signal, the single-phase voltage corresponding to the voltage sampling signal can be judged to be normal, and a high-level signal is output to the switch branch 32, so that the switch branch can be further judged; when the voltage value corresponding to the voltage sampling signal is greater than or less than the voltage value corresponding to the reference voltage signal, judging that the corresponding single-phase voltage is abnormal, and outputting a low-level signal; in practical applications, since the collection object of the voltage sampling circuit 10 is an alternating current, the reference voltage can be an alternating current voltage matched with the alternating current. In an alternative embodiment, the threshold voltage is 5V. Of course, in other embodiments, it may also be possible to output a high level signal when determining that the corresponding single-phase voltage is normal.

Referring to fig. 1 to 5, in an embodiment of the present invention, the controlled ends of the switch branches 321 are connected to the output ends of the switch control branches 311 in a plurality of ways in a one-to-one correspondence manner, the input ends of the switch branches 321 in a plurality of ways are respectively connected to the output end of the main controller 20, and the output ends of the switch branches 321 in a plurality of ways are respectively connected to the gate poles of the corresponding thyristors in a one-to-one correspondence manner; each switch branch 321 is configured to adjust the driving signal output by the main controller according to the switch control signal, and output the adjusted driving signal to control on/off of each thyristor in the thyristor rectification circuit.

In this embodiment, the switch branches 321 (in this embodiment, the reference numeral 321 represents one switch branch for explanation) may be implemented by using one or more combinations of an and gate, an or gate, and a not gate to construct a logic determination circuit, and each switch branch 321 acts under the control of one switch control branch 311. Specifically, the method comprises the following steps of; when the accessed driving signal is an abnormal high level signal (in practical application, when a software program in the main controller is not reliable enough or the driving signal is abnormal due to runaway, a low level signal in the driving signal is converted into an abnormal high level signal to be output), and at this time, the switching branch 321 receives that the switching control signal output by the corresponding switching control branch 311 is a low level signal, so that the driving signal can be judged to be abnormal, and at this time, the switching branch 321 can adjust the driving signal, so that the abnormal high level signal cannot be output to the gate of the thyristor; during normal operation, the switch branch 321 receives the switch control signal as a high level signal, and can normally output the driving signal output by the main controller 20 to the corresponding thyristor, so as to drive the thyristor rectifier circuit 80 to perform rectification. In an alternative embodiment, each of the switch branches 321 is implemented by an and gate.

Referring to fig. 1 to 5, in an embodiment of the present invention, the silicon controlled driving circuit further includes:

the signal modulation circuit 40 is respectively connected with the output ends of the multiple voltage sampling circuits 10 and the input end of the main controller 20, and is used for outputting the voltage sampling signals to the main controller 20 after operational amplification;

and the power amplification circuit 50 is respectively connected with the output end of the monitoring circuit 30 and the gate electrode of the corresponding controlled silicon, and is used for amplifying the power of the driving signal output by the monitoring circuit 30 after adjustment and outputting the driving signal to the gate electrode of the corresponding controlled silicon.

In this embodiment, the signal modulation circuit 40 may be implemented by an operational amplifier integrated circuit, and in practical applications, the parameter value of the voltage sampling signal is far lower than the requirement of the main controller 20 for the input signal, so that the signal modulation circuit 40 is configured to output a plurality of voltage sampling signals to the main controller 20 after operational amplification, so as to meet the input requirement of the main controller 20. The principle of the power amplifier circuit 50 is the same as that of the signal modulation circuit 40, and is not described in detail herein. The power amplifier circuit 50 is used for outputting the driving signal output by the main controller 20 to the gate of the corresponding thyristor after operational amplification, so that the driving signal meets the driving requirement of the thyristor, and the thyristor can work according to the driving signal output by the main controller 20 during normal work.

Referring to fig. 1 to 5, in an embodiment of the present invention, the silicon controlled driving circuit further includes: the multi-path voltage detection circuit 60 is used for detecting the voltage between the anode and the cathode of each silicon controlled rectifier in the silicon controlled rectifier rectification circuit and outputting a corresponding voltage detection signal to the main controller;

and the main controller is also used for determining the voltage between the anode and the cathode of each controllable silicon according to the voltage detection signal and generating a corresponding driving signal.

In this embodiment, the number of the voltage detection circuit 60 is matched with the number of the thyristors in the thyristor rectification circuit 80, and is not limited herein. The voltage detection circuit 60 is configured to obtain voltage conditions at two ends of each thyristor in real time, and output a corresponding voltage detection signal, so that the main controller 20 can determine on/off conditions of each thyristor according to the corresponding voltage detection signal, and generate a corresponding driving signal according to a determination result to continuously drive on/off of each thyristor. By the arrangement, when the controllable silicon stops working due to the fact that the software program runs away, the main controller can adjust the driving signal generated by the main controller in real time, and then the frequency converter is enabled to recover to normal operation.

The utility model also provides a frequency converter, this frequency converter includes:

an ac input 70 for receiving an ac voltage;

the silicon controlled rectifier circuit 80, the said silicon controlled rectifier circuit 80 includes at least one silicon controlled rectifier; and

the thyristor drive circuit as described above;

the input end of the silicon controlled rectifier rectifying circuit 80 is connected with the alternating current input end 70, and the controlled end of the silicon controlled rectifier rectifying circuit 80 is connected with the output end of the silicon controlled rectifier driving circuit; the thyristor rectification circuit 80 is used for converting the accessed alternating current voltage into direct current voltage and outputting the direct current voltage according to the thyristor driving signal output by the thyristor driving circuit.

Further, the silicon controlled rectifier circuit 80 is a single-phase bridge rectifier circuit;

or, the silicon controlled rectifier circuit 80 is a three-phase bridge type full-controlled rectifier circuit;

or, the thyristor rectification circuit 80 is a three-phase bridge type half-controlled rectification circuit.

The detailed structure of the silicon controlled driving circuit can refer to the above embodiment, and is not described herein again; it can be understood that, because the silicon controlled drive circuit is used in the frequency converter, the embodiment of the frequency converter includes all technical solutions of all embodiments of the silicon controlled drive circuit, and the achieved technical effects are also completely the same, and are not described herein again.

In this embodiment, the AC input 70 may be connected to the power grid or other DC-AC power source for receiving single-phase or three-phase AC power. The thyristor rectifier circuit 80 may be a single-phase bridge rectifier circuit or a three-phase rectifier circuit; the type of the rectification circuit can be a fully-controlled rectification circuit or a semi-controlled rectification circuit, and is not limited herein. It can be understood that, when the thyristor rectifier circuit 80 is a single-phase bridge rectifier circuit, the ac input terminal 70 is used for receiving single-phase ac power; when the thyristor rectifier circuit 80 is a three-phase bridge rectifier circuit, the ac input terminal 70 is used for receiving three-phase ac power. However, no matter what type the thyristor rectifier circuit 80 is, the thyristor rectifier circuit is used for outputting various driving signals according to the main controller 20 to drive the thyristor to work, so that the alternating current voltage accessed by the alternating current input end 70 is rectified into direct current voltage and then output.

Referring to fig. 1 to 5, in an embodiment of the present invention, when the scr circuit 80 is a three-phase bridge type half-controlled rectifier circuit, the anode of each scr in the scr circuit 80 is connected to the ac input terminal 70, each of the cathodes of the thyristors are connected to each other through a positive voltage bus, and the ground terminal of the scr driving circuit is connected to the positive voltage bus.

Further, when the silicon controlled rectifier circuit 80 is a three-phase bridge type half-controlled rectifier circuit; the three-phase bridge rectification circuit comprises a first silicon controlled rectifier S1, a second silicon controlled rectifier S2, a third silicon controlled rectifier S3, a first switching tube T1, a second switching tube T2 and a third switching tube T3; anodes of the first thyristor S1, the second thyristor S2 and the third thyristor S3 are respectively connected with cathodes of the first switch tube T1, the second switch tube T2 and the third switch tube T3 in a one-to-one correspondence manner, cathodes of the first thyristor S1, the second thyristor S2 and the third thyristor S3 are connected with a positive electrode output end of the thyristor rectification circuit 80 through a positive voltage bus P, and anodes of the first switch tube T1, the second switch tube T2 and the third switch tube T3 are connected with a negative electrode output end of the thyristor rectification circuit 80 through a negative voltage bus N; the controlled ends of the first controllable silicon S1, the second controllable silicon S2 and the third controllable silicon S3 are respectively connected with the output end of the controllable silicon driving circuit; the common ends of the first thyristor S1 and the first switch tube T1, the second thyristor S2 and the second switch tube T2, and the third thyristor S3 and the third switch tube T3 are the three-phase input ends of the three-phase bridge rectifier circuit, respectively.

Further, the frequency converter further includes a bus capacitor C and an inverter 90;

one end of the bus capacitor C is connected with the positive output end of the silicon controlled rectifier circuit 80, and the other end of the bus capacitor C is connected with the negative output end of the silicon controlled rectifier circuit 80;

the inverter 90 is connected in parallel with the bus capacitor C.

In this embodiment, the thyristor rectifier circuit 80 is a three-phase bridge type half-controlled rectifier circuit. Of course, in other alternative embodiments, a three-phase bridge full-control rectification circuit, a single-phase bridge half-control rectification circuit, and a single-phase bridge full-control rectification circuit may also be used. The silicon controlled rectifier circuit 80 is used for outputting the rectified dc voltage to the inverter 90 through the positive and negative voltage buses N and the bus capacitor C. The bus capacitor C is used for flattening a direct current voltage output by the rectifying circuit to a minimum alternating current component, and providing a pure direct current voltage for the subsequent inverter 90 so as to reduce waveform distortion of the alternating current voltage output by the inverter 90; and bus capacitor C need carry out the precharge at the power-on initial stage of converter, and adopt this embodiment silicon controlled rectifier drive circuit can need not to set up current-limiting resistor when the power-on, limits power-on impulse current, is favorable to reducing the system volume, reduces the cost of converter, can also reduce the complexity of converter circuit control simultaneously, is favorable to the overall arrangement of automatically controlled subassembly PCB board.

In an alternative embodiment, referring to fig. 3, the ac input 70 is connected to the three-phase grid ac voltage (R, S, T). Wherein, RP, SP and TP output by the voltage sampling circuit 10 are voltage sampling values of each ac voltage in the three-phase ac voltages respectively corresponding to the positive bus voltage, Udc + and Udc-are voltage values of the positive voltage bus and the negative voltage bus respectively output after being rectified by the thyristor rectification circuit 80, and the first switching tube T1, the second switching tube T2 and the third switching tube T3 may all be diodes.

The above is only the optional embodiment of the present invention, and not therefore the limit of the patent scope of the present invention, all of which are in the concept of the present invention, the equivalent structure transformation of the content of the specification and the drawings is utilized, or the direct/indirect application is included in other related technical fields in the patent protection scope of the present invention.

Claims (12)

1. The utility model provides a silicon controlled rectifier drive circuit, its characterized in that, silicon controlled rectifier drive circuit is used for driving silicon controlled rectifier circuit work, including at least one silicon controlled rectifier in the silicon controlled rectifier circuit, silicon controlled rectifier drive circuit includes:

the multi-path voltage sampling circuit is connected with the input end of the silicon controlled rectifier circuit and is used for respectively detecting the multiphase alternating current voltage input to the silicon controlled rectifier circuit and outputting corresponding voltage sampling signals;

the main controller is connected with the output ends of the voltage sampling circuits and used for outputting a driving signal according to the voltage sampling signal; and

the first end of the monitoring circuit is connected with the output ends of the voltage sampling circuits, the second end of the monitoring circuit is connected with the output end of the main controller, and the third end of the monitoring circuit is the output end of the silicon controlled rectifier driving circuit;

the monitoring circuit is used for adjusting the driving signal output by the main controller according to the voltage sampling signal and outputting the adjusted driving signal to control the on-off of each silicon controlled rectifier in the silicon controlled rectifier circuit.

2. The silicon controlled drive circuit as claimed in claim 1, wherein said monitoring circuit comprises a multi-way switch control branch and a multi-way switch branch;

the input end of the switch control branch is the first end of the monitoring circuit, the output end of the switch control branch is connected to the control end of the switch branch, the input end of the switch branch is the second end of the monitoring circuit, and the output end of the switch branch is the third end of the monitoring circuit.

3. The silicon controlled rectifier drive circuit as claimed in claim 2, wherein each of said switch control branches has a first input terminal for one-to-one connection with a plurality of voltage sampling circuits and a second input terminal for receiving a reference voltage signal;

the switch control branch is configured to compare the voltage sampling signal with the reference voltage signal, and output a switch control signal, so that the switch branch 32 can operate according to the switch control signal.

4. The silicon controlled rectifier drive circuit as claimed in claim 3, wherein each of said switch control branches includes a voltage comparator, a first resistor, a second resistor; the reverse end of the voltage comparator is a first input end of the switch control branch circuit, the in-phase end of the voltage comparator is a second input end, the in-phase end of the voltage comparator is also connected with one end of the second resistor through the first resistor, and the other end of the second resistor is used for connecting a threshold voltage; and the output end of the voltage comparator is connected with the common end of the first resistor and the second resistor to form the output end of the switch control branch circuit.

5. The silicon controlled rectifier driving circuit according to claim 3, wherein the controlled terminals of a plurality of the switching branches are connected with the output terminals of a plurality of the switching control branches in a one-to-one correspondence manner, the input terminals of a plurality of the switching branches are respectively connected with the output terminal of the main controller, and the output terminals of a plurality of the switching branches are respectively connected with the gate poles of the corresponding silicon controlled rectifiers in a one-to-one correspondence manner; each switch branch circuit is used for adjusting the driving signal output by the main controller according to the switch control signal and outputting the adjusted driving signal to control the on-off of each silicon controlled rectifier in the silicon controlled rectifier circuit.

6. The thyristor driver circuit as claimed in claim 1, wherein said thyristor driver circuit further comprises:

the signal modulation circuit is respectively connected with the output ends of the voltage sampling circuits and the input end of the main controller and is used for outputting the voltage sampling signals to the main controller after operational amplification;

and the power amplification circuit is respectively connected with the output end of the monitoring circuit and the gate pole of the corresponding controlled silicon and is used for amplifying the power of the driving signal output by the monitoring circuit after adjustment and outputting the driving signal to the gate pole of the corresponding controlled silicon.

7. The thyristor driver circuit as claimed in claim 1, wherein said thyristor driver circuit further comprises: the multi-path voltage detection circuit is used for detecting the voltage between the anode and the cathode of each silicon controlled rectifier in the silicon controlled rectifier rectification circuit and outputting corresponding voltage detection signals to the main controller;

and the main controller is also used for determining the voltage between the anode and the cathode of each controllable silicon according to the voltage detection signal and generating a corresponding driving signal.

8. A frequency converter, characterized in that the frequency converter comprises:

the alternating current input end is used for accessing alternating current voltage;

the silicon controlled rectifier circuit comprises at least one silicon controlled rectifier; and

a thyristor drive circuit according to any one of claims 1 to 7;

the input end of the silicon controlled rectifier circuit is connected with the alternating current input end, and the controlled end of the silicon controlled rectifier circuit is connected with the output end of the silicon controlled rectifier driving circuit; the silicon controlled rectifier circuit is used for converting the accessed alternating voltage into direct current voltage and outputting the direct current voltage according to the silicon controlled rectifier driving signal output by the silicon controlled rectifier driving circuit.

9. The frequency converter according to claim 8, wherein the thyristor rectifier circuit is a single-phase bridge rectifier circuit;

or the silicon controlled rectifier circuit is a three-phase bridge type full-control rectifier circuit;

or the silicon controlled rectifier circuit is a three-phase bridge type semi-controlled rectifier circuit.

10. The frequency converter according to claim 9, wherein when the thyristor rectifier circuit is a three-phase bridge type half-controlled rectifier circuit, an anode of each thyristor in the thyristor rectifier circuit is connected to the ac input terminal, a cathode of each thyristor is connected to each other through a positive voltage bus, and a ground terminal of the thyristor drive circuit is connected to the positive voltage bus.

11. The frequency converter according to claim 9, wherein when the thyristor rectifier circuit is a three-phase bridge half-controlled rectifier circuit; the three-phase bridge rectifier circuit comprises a first silicon controlled rectifier, a second silicon controlled rectifier, a third silicon controlled rectifier, a first switching tube, a second switching tube and a third switching tube; anodes of the first silicon controlled rectifier, the second silicon controlled rectifier and the third silicon controlled rectifier are respectively connected with cathodes of the first switch tube, the second switch tube and the third switch tube in a one-to-one correspondence manner, cathodes of the first silicon controlled rectifier, the second silicon controlled rectifier and the third silicon controlled rectifier are connected with a positive electrode output end of the silicon controlled rectifier circuit through a positive voltage bus, and anodes of the first switch tube, the second switch tube and the third switch tube are connected with a negative electrode output end of the silicon controlled rectifier circuit through a negative voltage bus; the controlled ends of the first controllable silicon, the second controllable silicon and the third controllable silicon are respectively connected with the output end of the controllable silicon driving circuit; the common ends of the first silicon controlled rectifier and the first switch tube, the second silicon controlled rectifier and the second switch tube, and the third silicon controlled rectifier and the third switch tube are respectively three-phase input ends of the three-phase bridge rectifier circuit.

12. The frequency converter according to any one of claims 8-11, wherein the frequency converter further comprises a bus capacitor and an inverter;

one end of the bus capacitor is connected with the positive output end of the silicon controlled rectifier circuit, and the other end of the bus capacitor is connected with the negative output end of the silicon controlled rectifier circuit;

the inverter is connected in parallel with the bus capacitor.

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