CN212435418U

CN212435418U - High-voltage direct-current seamless switching control device

Info

Publication number: CN212435418U
Application number: CN202020931529.6U
Authority: CN
Inventors: 高正杰; 齐正宇; 来华星
Original assignee: Hefei Tongzhi Electrical Control Technology Co ltd
Current assignee: Hefei Tongzhi Electrical Control Technology Co ltd
Priority date: 2020-05-27
Filing date: 2020-05-27
Publication date: 2021-01-29
Anticipated expiration: 2030-05-27

Abstract

The utility model discloses a high voltage direct current seamless switching control device in the field of power switching, which comprises a standby direct current input and at least two paths of high voltage direct current inputs which are connected to a bus through a fourth diode, a high voltage controller, a contactor connected on a high voltage direct current input line and an IGBT pre-charging circuit connected on the standby direct current input; the high-voltage controller is used for comparing and outputting a comparison voltage of a bus voltage sampled by the high-voltage controller with a preset reference voltage so as to control the on-off of the IGBT pre-charging circuit, and is also used for sampling an input voltage of a standby direct current input and each high-voltage direct current input line so as to control the on-off of a contactor on the high-voltage direct current input line. The utility model discloses a seamless switching between a plurality of high voltage direct current inputs, when the task was carried out, need not frequent disconnection/switch-on operation equipment, guaranteed that the high efficiency of task is accomplished.

Description

High-voltage direct-current seamless switching control device

Technical Field

The utility model relates to a power switching field specifically is a seamless handover control device of high voltage direct current.

Background

In the field of high-voltage control, high-voltage direct-current seamless switching of various power source inputs is one of important problems to be considered in product design. Along with the diversification of power supplies and the improvement of the uninterrupted power supply requirement of vehicle-mounted equipment, a high-voltage control system puts forward higher requirements on a seamless switching control device.

The high-voltage direct-current switching control device input by various power sources can be short-term powered off in the switching process of the load equipment at present, seamless switching cannot be met, and the short-term powered off of the load equipment can influence the operation state when a task is executed, so that the task cannot be completed satisfactorily.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a seamless handover control device of high voltage direct current to solve the problem that proposes in the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme:

a high-voltage direct current seamless switching control device comprises a standby direct current input and at least two paths of high-voltage direct current inputs which are connected to a bus through a fourth diode, a high-voltage controller, a contactor connected to a high-voltage direct current input line and an IGBT pre-charging circuit connected to the standby direct current input; the high-voltage controller is used for comparing and outputting a comparison voltage of a bus voltage sampled by the high-voltage controller with a preset reference voltage so as to control the on-off of the IGBT pre-charging circuit, and is also used for sampling an input voltage of a standby direct current input and each high-voltage direct current input line so as to control the on-off of a contactor on the high-voltage direct current input line.

As an improvement of the present invention, in order to prevent the problem of high current during power-on caused by capacitive load, a bus resistor pre-charging circuit is connected between the high voltage dc input, the standby dc input and the bus, and the bus resistor pre-charging circuit includes a high voltage auxiliary power module, a fourth contactor and at least three power diodes; the cathodes of the power diodes are connected with the high-voltage auxiliary power supply module and the first end of the fourth contactor, and the anodes of the power diodes are correspondingly connected with the standby direct-current input line and the high-voltage direct-current input line respectively; and the fourth contactor is controlled to be switched on and switched off by the high-voltage controller, and the second end of the fourth contactor is connected to the bus side by a resistor R1 and the fourth diode.

As the utility model discloses an improvement scheme, when only inserting the circuit by one of them high voltage direct current input, the voltage mistake that causes by the reverse leakage current of the power diode on other high voltage direct current circuit is sampled in order to prevent, all be connected with the resistance board between the positive negative pole of high voltage direct current input and reserve direct current input, the negative pole side of resistance board is earthed altogether.

As an improved scheme of the present invention, in order to realize a good pre-charging effect of the IGBT pre-charging circuit when the load is capacitive, the IGBT pre-charging circuit includes an IGBT power tube driven by the high-voltage controller, a third contactor connected to an output end of the IGBT power tube, and a pre-charging resistor R2 connected in parallel to two ends of the third contactor, wherein the resistor R2 is a wire spring resistor; a sixth diode and a resistor R3 are further connected between the IGBT power tube and the third contactor, the cathode of the sixth diode is connected with the first end of the resistor R3 and the output end of the IGBT power tube, and the anode of the sixth diode and the second end of the resistor R3 are grounded; the third contactor is connected to a bus side through a fifth diode.

As the utility model discloses an improvement scheme, when the bus sampling voltage appearance is unusual in order to realize, drive IGBT pre-charging circuit break-make in time, high pressure controller includes two voltage comparator, voltage comparator's inverting input bus sampling voltage, its homophase output input have the reference voltage who sets up through reference circuit, voltage comparator comparison bus sampling voltage and reference voltage to output comparison voltage to the primary side of optical coupler, the secondary side of optical coupler is connected IGBT power tube drive end.

Has the advantages that: the utility model provides a seamless switching controlling means of high voltage direct current utilizes high voltage controller to the break-make of the comparative voltage drive IGBT pre-charging circuit of the busbar voltage of sampling and reference voltage for reserve direct current input has realized the seamless switching between a plurality of high voltage direct current inputs as transition power supply, thereby solves current high voltage direct current switching controlling means and falls the electricity at switching in-process load equipment, influences the problem of the normal execution of operation task. The task completion progress can be accelerated, the task equipment does not need to be switched on/off frequently in the task execution process, and the high-efficiency completion of the task is ensured.

Drawings

Fig. 1 is a schematic circuit diagram of the present invention;

fig. 2 is a schematic diagram of an implementation of a voltage comparator inside the high voltage controller.

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 work belong to the protection scope of the present invention.

Embodiment 1, a high voltage dc seamless switching control device, including a standby dc input and at least two high voltage dc inputs connected to a bus through a fourth diode, further including a high voltage controller, a contactor connected to a high voltage dc input line, and an IGBT pre-charge circuit connected to the standby dc input; the high-voltage controller is used for comparing and outputting a comparison voltage of a bus voltage sampled by the high-voltage controller with a preset reference voltage so as to control the on-off of the IGBT pre-charging circuit according to the comparison voltage, and is also used for sampling an input voltage on a standby direct current input line and each high-voltage direct current input line, judging a high-voltage direct current input circuit to be switched according to the sampled input voltage so as to control the on-off of a contactor on the high-voltage direct current input line.

The present embodiment samples the bus voltage and the input voltage on each input line (standby dc input and each high voltage dc input) via the high voltage controller. When the bus voltage is monitored to be abnormal, firstly, the high-voltage controller compares the bus voltage with the reference voltage and outputs the comparison voltage, and the us-level controller controls the on-state of the IGBT pre-charging circuit, so that the standby direct current input is started immediately to be on, the power supply of the load equipment at the bus side is maintained, and the power failure of the load equipment is prevented.

And when the standby direct current input is detected to be stable, the contactor on the current high-voltage direct current input line with the abnormality is disconnected, namely, before the contactor on the current high-voltage direct current input line is disconnected, the current abnormal high-voltage direct current input and the standby direct current input simultaneously supply power to the bus.

After the contactor on the current abnormal high voltage dc input line is cut, there is a continuous sampling of the input voltage of each high voltage dc input due to the high voltage controller. Therefore, according to the sampling result of the input voltage, after the high-voltage controller judges that no abnormity exists, the high-voltage controller can switch to be connected with a contactor on the other high-voltage direct-current input line, and the IGBT pre-charging circuit on the standby direct-current input and the connected high-voltage direct-current line coexist at the moment. When the high-voltage direct current input is stable, the voltage of the bus is recovered to be stable, the high-voltage controller turns off the IGBT pre-charging circuit according to the comparison voltage output by the sampling voltage of the bus and the reference voltage, namely, the standby direct current input is turned off, and the seamless switching between the high-voltage direct current input can be realized.

Embodiment 2, as shown in fig. 1, this embodiment takes two high voltage dc inputs as an example, which are a first high voltage dc input and a second high voltage dc input respectively. A first contactor K1 is connected to a first high-voltage direct-current input line, and a second contactor K2 is connected to a second high-voltage direct-current input line. The high voltage controller respectively samples voltage on the lines of the first high voltage direct current input, the second high voltage direct current input and the standby direct current input.

Further, a bus resistor pre-charging circuit is connected among the first direct current input, the second direct current input, the standby direct current input and the bus, the bus resistor pre-charging circuit comprises a high-voltage auxiliary power supply module and a fourth contactor K4, and the power diodes comprise a first diode D1, a second diode D2 and a third diode D3; cathodes of the first diode D1, the second diode D2 and the third diode D3 are all connected with the high-voltage auxiliary power supply module and a first end of a fourth contactor K4, and an anode of the first diode D1 is connected to a line of the standby direct-current input; the anode of the second diode D2 is connected to the line of the second high-voltage direct-current input, and the anode of the third diode D3 is connected to the line of the first high-voltage direct-current input; the fourth contactor K4 is controlled by the high voltage controller, and the second end of the fourth contactor K4 is connected to the bus side through the fourth diode D4 of the resistor R1 stage.

After the first diode D1, the second diode D2 and the third diode D3 are connected in parallel, the fourth contactor K4 is controlled to be attracted firstly, the problem of electrifying large current caused by the fact that load equipment on the output side of the bus is capacitive load is solved, if the load equipment is clear to be pure resistance load, a bus resistance pre-charging circuit can be omitted, and the size space of the layout of the internal structure is further reduced.

Further, resistance plates are connected between the positive and negative electrodes of the high-voltage direct current input and the standby direct current input, and the negative electrode sides of the resistance plates are grounded.

The resistance board is used for preventing voltage missampling caused by reverse leakage current of a second diode D2 on a second high-voltage direct-current input line when a first high-voltage direct-current input is connected and a second high-voltage direct-current input is not in the current, and resistors are connected in parallel at input ends of all the lines, so that resistance values passed by the reverse leakage current are reduced, and voltage missampling caused by the reverse leakage current is avoided. The same principle applies when the first high voltage dc input is not present and the second high voltage dc input is switched in.

Further, the IGBT pre-charging circuit comprises an IGBT power tube driven by the high-voltage controller, a third contactor K3 connected to the output end of the IGBT power tube, and a pre-charging resistor R2 connected in parallel to two ends of the third contactor K3, wherein the resistor R2 is a wire spring resistor; a sixth diode D6 and a resistor R3 are further connected between the IGBT power tube and the third contactor K3, the cathode of the sixth diode D6 is connected with the first end of the resistor R3 and the output end of the IGBT power tube, and the anode of the sixth diode D6 and the second end of the resistor R3 are grounded; the third contactor K3 is connected to the bus side through a fifth diode D5.

When the bus-side load equipment is a capacitive load, after the pre-charging of the bus resistor pre-charging circuit, the pre-charging of the capacitor does not reach more than 90% of the ideal pre-charging effect, and the IGBT pre-charging circuit is adopted to pre-charge the capacitor for the second time. The pre-charging resistor R2 is a metal wire spring resistor, and is characterized by burning resistance, the resistance value is about 0.6 ohm, and is far lower than the equivalent resistance of load equipment. Generally, the equivalent resistance of the high-voltage load device is more than 200 ohms, so the IGBT pre-charging circuit in the embodiment can achieve an ideal pre-charging effect. The pre-charging resistor R2 can also reduce the impact current of the bus and reduce the peak impact of the impact current on the IGBT power tube.

The overall operation in fig. 1 is as follows: after the pre-charging of the bus resistor pre-charging circuit is completed, the first high-voltage direct-current input with the highest priority is connected to the bus, even if the actual voltage is not higher than the second high-voltage direct-current input voltage. The high-voltage controller controls the first contactor K1 to be connected into an output bus, and the rear-stage load equipment is started to normally run. The second high-voltage direct current input is normally connected with the first high-voltage direct current input.

When seamless switching (sudden power failure or abnormal input of a first high-voltage direct-current input) is to occur, namely switching is performed to a second high-voltage direct-current input, the standby direct-current input end is transited at first, the transition time can be set according to actual requirements, and the high-voltage controller controls an IGBT power tube in a standby direct-current input line to start a hand-pulling function, namely, the standby direct-current input is equivalent to two hands of a person, the first high-voltage direct-current input and the standby direct-current input exist for a certain time before being disconnected, and the time can be set according to actual project requirements. And after the standby direct current input line is stabilized, the first high-voltage direct current input is disconnected, the load equipment is powered by the standby direct current input line for a short time, and the power supply time can be set according to project requirements. And then pulling a second high-voltage direct-current input, namely pulling a second contactor K2 on a second high-voltage direct-current input line, so that the second high-voltage direct-current input and the standby direct-current input exist for a certain time at the same time, and the time can be set according to the actual project requirements. And after the second high-voltage direct current input stably operates, the standby direct current input is disconnected, and the second high-voltage direct current input stably operates for a long time. And the standby direct current input plays an emergency function, and the seamless switching process to the low priority is ended when the high priority is suddenly powered off or the input is abnormal. When the high priority input fails clear, requiring the low priority to be switched back to the high priority, the process steps are similar as above. When the high-voltage controller detects that the bus is abnormal, the high-voltage controller switches into the power battery circuit in a us level mode, and in the us level switching process, the bus load equipment can be prevented from power failure and seamless switching can be achieved

Further, referring to fig. 2, the high voltage controller includes two voltage comparators N4A and N4B, an inverting input terminal of the voltage comparator N4A (model: LM2903D) is connected to the sampling bus voltage through a resistor R62, and a non-inverting input terminal is connected to a reference voltage provided by a reference circuit formed by resistors R66, R68, R67, R69, R26 and a potentiometer R81. In the reference circuit, a resistor R66 is connected in parallel with a resistor R68, one common end of the resistor R66 is connected with a +5V power supply, the other common end of the resistor R67, the resistor R29 and the resistor R26 which are connected in parallel and the common end of a potentiometer R81 are connected, and the first end of a resistor R59 and the non-inverting input end of a voltage comparator N4A are also connected. The resistors R67, R69 and R26 are grounded with the other common end of the potentiometer R81, and are connected to the non-inverting input end of the voltage comparator N4A through a capacitor C73; the second end of the resistor R59 is connected to the output end of the voltage comparator N4A.

The voltage comparator N4B is similar to the N4Ade connection circuit, and the inverting input end of the voltage comparator is connected with the bus sampling voltage through a resistor R82. The +5V power supply is connected to one common end of the resistors R87 and R90 which are connected in parallel, and the other common end is connected with the inverting input end of the voltage comparator N4B. The resistors R88, R91, R34 and the potentiometer R136 are connected in parallel, wherein one common end is connected with the inverting input end of the voltage comparator N4B, the other common end is grounded, and the other common end is connected with the inverting input end of the voltage comparator N4B through the capacitor C89. A resistor R63 is also connected between the non-inverting input end of the voltage comparator N4B and the output end thereof.

The 2 pins of the primary side of the optocoupler E21(B-TLP291) are connected with the output ends of the voltage comparators N4A and N4B, and the 1 pin of the optocoupler is connected with a +5V power supply through a resistor R55. The 3 pins of the secondary side of the optical coupler E21 are grounded, a capacitor C75 is connected between the 3 pins and the 4 pins, the 4 pins are connected to a +5V power supply through a resistor R56, and the 4 pins are connected to the driving end of the IGBT power tube.

The normal input range of the bus voltage is DC450V-DC700V, when the output bus voltage is abnormal, after R66 and R68 are connected in parallel, the output bus voltage is divided after being connected in parallel with R67, R69, R26 and a potentiometer R81, the output of the voltage comparator N4A is changed into low level once the bus voltage is greater than DC705V, so that an optical coupler E21 is conducted, an IGBT power tube on a standby direct current input line is controlled to be conducted and attracted, and a us-level control IGBT power tube enables a us-level standby direct current input line to be switched into an output bus. The resistor R59 determines the response sensitivity and the response time, and can be adjusted according to actual requirements.

When the bus voltage is less than DC445V, after the R87 and the R90 are connected in parallel, the voltage is divided by the R88, the R91, the R34 and the potentiometer R136 in parallel, the voltage is compared with the bus sampling voltage, the output of the voltage comparator N4B is changed into low level, the optical coupler E21 is conducted, the IGBT power tube on the standby direct current input line is controlled to be conducted and attracted, and the us level controls the IGBT power tube, so that the us level of the standby direct current input line is switched into the output bus. R63 determines the response sensitivity and the response time, and can be adjusted according to actual requirements.

The utility model provides a seamless switching controlling means of high voltage direct current utilizes high voltage controller to the break-make of the comparative voltage drive IGBT pre-charging circuit of the busbar voltage of sampling and reference voltage for reserve direct current input has realized the seamless switching between a plurality of high voltage direct current inputs as transition power supply, thereby solves current high voltage direct current switching controlling means and falls the electricity at switching in-process load equipment, influences the problem of the normal execution of operation task. The task completion progress can be accelerated, the task equipment does not need to be switched on/off frequently in the task execution process, and the high-efficiency completion of the task is ensured.

Although the present description is described in terms of embodiments, not every embodiment includes only a single embodiment, and such description is for clarity only, and those skilled in the art should be able to integrate the description as a whole, and the embodiments can be appropriately combined to form other embodiments as will be understood by those skilled in the art.

In the description of the present invention, it is noted that relational terms such as first and second, and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

In the description of the present invention, it should be further noted that the terms "upper", "lower", "inner", "outer", and the like indicate the position or positional relationship based on the position or positional relationship shown in the drawings, or the position or positional relationship which is usually placed when the products of the present invention are used, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Therefore, the above description is only a preferred embodiment of the present application, and is not intended to limit the scope of the present application; all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A high-voltage direct current seamless switching control device comprises a standby direct current input and at least two paths of high-voltage direct current inputs which are connected to a bus through a fourth diode, and is characterized by further comprising a high-voltage controller, a contactor connected to a high-voltage direct current input line and an IGBT pre-charging circuit connected to the standby direct current input; the high-voltage controller is used for comparing and outputting a comparison voltage of a bus voltage sampled by the high-voltage controller with a preset reference voltage so as to control the on-off of the IGBT pre-charging circuit, and is also used for sampling an input voltage of a standby direct current input and each high-voltage direct current input line so as to control the on-off of a contactor on the high-voltage direct current input line.

2. The high-voltage direct current seamless switching control device according to claim 1, wherein a bus resistor pre-charging circuit is connected between the high-voltage direct current input, the standby direct current input and the bus, and the bus resistor pre-charging circuit comprises a high-voltage auxiliary power supply module, a fourth contactor and at least three power diodes; the cathodes of the power diodes are connected with the high-voltage auxiliary power supply module and the first end of the fourth contactor, and the anodes of the power diodes are correspondingly connected with the standby direct-current input line and the high-voltage direct-current input line respectively; and the fourth contactor is controlled to be switched on and switched off by the high-voltage controller, and the second end of the fourth contactor is connected to the bus side by a resistor R1 and the fourth diode.

3. The device according to claim 2, characterized in that a resistance plate is connected between the positive and negative poles of the high-voltage direct current input and the standby direct current input, and the negative poles of the resistance plates are connected to the same ground.

4. The high-voltage direct-current seamless switching control device according to claim 2 or 3, wherein the IGBT pre-charging circuit comprises an IGBT power tube driven by the high-voltage controller, a third contactor connected to an output end of the IGBT power tube, and a pre-charging resistor R2 connected in parallel across the third contactor, and the pre-charging resistor R2 is a wire spring resistor; a sixth diode and a resistor R3 are further connected between the IGBT power tube and the third contactor, the cathode of the sixth diode is connected with the first end of the resistor R3 and the output end of the IGBT power tube, and the anode of the sixth diode and the second end of the resistor R3 are grounded; the third contactor is connected to a bus side through a fifth diode.

5. The high-voltage direct current seamless switching control device according to claim 4, wherein the high-voltage controller comprises two voltage comparators, the inverting input end of each voltage comparator inputs a bus sampling voltage, the non-inverting output end of each voltage comparator inputs a reference voltage set through a reference circuit, each voltage comparator compares the bus sampling voltage with the reference voltage and outputs the comparison voltage to the primary side of the optical coupler, and the secondary side of the optical coupler is connected with the driving end of the IGBT power tube.