Grid-connected and off-grid control circuit and grid-connected and off-grid control cabinet

Abstract

The utility model relates to a grid-connected and off-grid control circuit and a grid-connected and off-grid control cabinet, and the grid-connected and off-grid control circuit enables a control unit of a commercial power side circuit breaker or an oil engine side circuit breaker to be connected in parallel with a single-board control unit for independent control through a multi-station change-over switch by introducing the multi-contact station change-over switch. The power taking mode of the commercial power side circuit breaker or the oil engine side circuit breaker is realized by connecting a group of normally closed contacts in the change-over switch in series, so that the normally closed contacts of the change-over switch are switched to a normally open state when a single-board control unit is changed, and then the output end of the under-voltage circuit breaker is in a cold state before a grid-connected and off-grid control mode is switched and is not electrified for a long time; and the whole work is safer and more reliable.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of safety circuit, specifically relates to a parallel and off -network control circuit, parallel and off -network control cabinet. BACKGROUND

[0002] The switching of parallel and off -network in the market at present is realized through automatic switching switch (ATS), and the switching time is long, generally is second level, and ATS can generally meet the design requirement in the low -power parallel and off -network working scene, but ATS cannot meet the use requirement of customer's quick switching in the high -power intelligent parallel and off -network scene, and independent control panel (such as frame type circuit breaker) is used to control parallel and off -network. Intelligent parallel and off -network control using control panel can meet the requirements of intelligent control and localization control, but the existence of power supply mode and electrical interlocking logic can cause the fluctuation of high and low level of control panel output, cannot guarantee reliable and effective switching of intelligent control and local operation state, in addition, the control mode of under -voltage module of frame circuit breaker in high -power environment often lacks electrical safety consideration, and comprehensively leads to many hidden dangers, and seriously causes short -circuit fault, damages internal devices of standby power cabinet, and even causes electrical fire.

[0003] Considering the above problems, in the standby power scene of oil engine and power hybrid application, circuit breakers are configured on the oil engine side and the power side respectively, the normally closed auxiliary contact of the circuit breaker on the power side is connected in series to the closed loop of the circuit breaker on the oil engine side, and the normally closed auxiliary contact of the circuit breaker on the oil engine side is connected in series to the short -term closed loop of the circuit breaker on the power side, so as to form electrical interlocking, this scheme can meet the working requirement of low -power parallel and off -network scene, but cannot meet the application requirement of various high -power parallel and off -network or with energy storage standby scene, for example, when the oil engine side is connected to the power grid system as an intelligent load, it is controlled by an independent control unit, and the oil engine side circuit breaker and the power side circuit breaker are attracted at the same time, therefore, the prior art cannot meet the requirement of interlocking and simultaneous attraction in different modes such as intelligent control and local operation control. In addition, the under -voltage release control of the under -voltage module of the circuit breaker is realized by the under -voltage control panel of the circuit breaker, and the time cannot meet the requirement of millisecond level quick release in the use scene, so an independent control panel is needed for control, but when the single -panel independent control is changed, the parallel relationship between the independently set control panel and the under -voltage release panel of the under -voltage module will cause the under -voltage release panel to be easily sent to the high effective state by reverse current for a long time, and there is a safety hazard.

[0004] Therefore, how to improve the peripheral control circuit of the under -voltage circuit breaker to overcome at least one of the above defects is a technical problem to be solved by the present application. UTILITY MODEL CONTENTS

[0005] The utility model discloses a main purpose is to overcome at least one of the above-mentioned defects, and it is to provide a parallel and off -network control circuit, parallel and off -network control cabinet can satisfy the parallel and off -network demand under different power size, and work safety, and the reliability is higher.

[0006] In order to achieve the above object, the utility model adopts technical scheme:

[0007] The utility model provides a parallel and off -network control circuit for parallel and off -network control to oil machine and commercial power, and parallel and off -network control circuit includes power supply switch, first control unit, second control unit, change -over switch, first undervoltage circuit breaker and second undervoltage circuit breaker, wherein:

[0008] The power supply switch is connected with the output end of commercial power or oil machine;

[0009] The change -over switch includes first normally open contact, second normally open contact, first normally closed contact, second normally closed contact and third normally closed contact;

[0010] The control end of first control unit is connected inductive coil in first undervoltage circuit breaker through first normally open contact and second normally open contact;

[0011] The power input end of second control unit is connected with third normally closed contact and power supply switch in series and constitutes undervoltage monitoring power taking circuit, and the output end of second control unit is connected inductive coil through first normally closed contact and second normally closed contact;

[0012] The normally closed auxiliary contact of second undervoltage circuit breaker is connected in series in undervoltage monitoring power taking circuit;

[0013] One of first undervoltage circuit breaker and second undervoltage circuit breaker is oil machine side undervoltage circuit breaker, and the other is commercial power side undervoltage circuit breaker.

[0014] According to one of the utility model's implementation ways, the power supply switch includes two connection terminals, it is first connection terminal and second connection terminal, wherein, first connection terminal is connected with the normally closed contact of second undervoltage circuit breaker in series after and is connected with one end of third normally closed contact, the other end of third normally closed contact is connected with one power input end of second control unit, and the other power input end of second control unit is connected with second connection terminal.

[0015] According to one of the utility model's implementation ways, the output positive pole and negative pole of commercial power or oil machine are connected with first connection terminal or second connection terminal respectively.

[0016] According to one of the embodiments of the utility model, the closing tripping mechanism of the first under-voltage circuit breaker is connected with the power supply switch, and a plurality of loads are connected on the connecting line between the closing tripping mechanism and the power supply switch.

[0017] According to one of the embodiments of the utility model, the indicator light of the first under-voltage circuit breaker is connected with the power supply switch.

[0018] In particular, the application also provides a parallel and off-grid control cabinet, which comprises the parallel and off-grid control circuit as described above.

[0019] Compared with the prior art, the parallel and off-grid control circuit and the parallel and off-grid control cabinet of the utility model patent application have the following advantages and beneficial effects:

[0020] The parallel and off-grid control circuit of the application has the following advantages: the control unit of the power supply side circuit breaker or the oil machine side circuit breaker and the single-board control unit controlled independently are connected in parallel through the multi-station change-over switch, the power supply mode of the power supply side circuit breaker or the oil machine side circuit breaker passes through a group of normally closed contacts in the series connection change-over switch, so that the normally closed contact of the change-over switch is switched to the normally open state when the single-board control unit is changed, and then the output end of the under-voltage circuit breaker is in a cold state and will not be electrified for a long time before the parallel and off-grid control mode is switched, so that the overall work is safer and more reliable.

[0021] In addition, the normally closed auxiliary contact of the oil machine side under-voltage circuit breaker is connected in series to the under-voltage monitoring power supply circuit of the power supply side under-voltage circuit breaker, and the normally closed auxiliary contact of the power supply side under-voltage circuit breaker is connected in series to the under-voltage monitoring power supply circuit of the oil machine side under-voltage circuit breaker, thereby forming the electrical interlocking of the power supply side under-voltage circuit breaker and the oil machine side under-voltage circuit breaker, so that they will not be closed at the same time during the under-voltage monitoring control process, and the working safety and reliability of the circuit breaker control unit during control can still be ensured. BRIEF DESCRIPTION OF DRAWINGS

[0022] Some specific embodiments of the utility model will be described in detail hereinafter with reference to the accompanying drawings in an exemplary but not limiting manner. The same reference signs in the drawings denote the same or similar components or parts. Those skilled in the art should understand that the drawings are not necessarily drawn to scale. In the drawings:

[0023] Figure 1 is a connection circuit schematic diagram of the under-voltage circuit breaker of the power supply side according to one embodiment of the utility model;

[0024] Figure 2 is a connection circuit schematic diagram of the under-voltage circuit breaker of the oil machine side according to one embodiment of the utility model. DETAILED DESCRIPTION

[0025] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present application.

[0026] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0027] Embodiment 1:

[0028] This embodiment describes a parallel and off-grid control circuit for parallel and off-grid control of an oil engine (mechanical generator, such as a diesel generator set) and commercial power. The parallel and off-grid control circuit includes a first under-voltage circuit breaker and a second under-voltage circuit breaker. In this embodiment, the first under-voltage circuit breaker is an under-voltage circuit breaker on the commercial power side, and the second under-voltage circuit breaker is an under-voltage circuit breaker on the oil engine side.

[0029] Figure 1 The connection circuit diagram of the under-voltage circuit breaker on the commercial power side includes a first power supply switch QF7, a first control unit GP1, a second control unit GP2, and a first changeover switch SA1, wherein:

[0030] The first power supply switch QF7 is connected to the commercial power output end;

[0031] The first changeover switch SA1 includes a first normally open contact, a second normally open contact, a first normally closed contact, a second normally closed contact, and a third normally closed contact;

[0032] The control end of the first control unit GP1 is connected to the inductive coil UVT in the first under-voltage circuit breaker QA1 through the first normally open contact and the second normally open contact;

[0033] The power input end of the second control unit GP2 is connected in series with the third normally closed contact and the first power supply switch QF7 to form an under-voltage monitoring power supply loop, and the output end of the second control unit GP2 is connected to the inductive coil UVT through the first normally closed contact and the second normally closed contact;

[0034] The normally closed auxiliary contact of the second under-voltage circuit breaker QA2 is connected in series in the under-voltage monitoring power supply loop.

[0035] The first power supply switch QF7 includes two connection terminals: a first connection terminal and a second connection terminal. The first connection terminal is connected in series with the normally closed contact of the second undervoltage circuit breaker QA2, and then connected to one end of the third normally closed contact. The other end of the third normally closed contact is connected to one power input terminal of the second control unit GP2. The other power input terminal of the second control unit GP2 is connected to the second connection terminal. The positive and negative terminals of the mains power output are connected to either the first connection terminal or the second connection terminal, respectively.

[0036] The closing trip mechanism CC of the first undervoltage circuit breaker QA1 is connected to the first power supply switch QF7, and several loads are connected on the connection line between the closing trip mechanism and the first power supply switch QF7. The indicator light M of the first undervoltage circuit breaker QA1 is connected to the first power supply switch QF7.

[0037] Figure 1 The diagram shows the initial state of the first undervoltage circuit breaker QA1 under its own control, where the second control unit controls the tripping mechanism of QA1. At this time, QA1 is energized. When the first transfer switch switches to automatic control, the second control unit controls the tripping mechanism of QA1. The normally closed contacts in the initial state become normally open contacts, and the normally open contacts become normally closed contacts. The induction coil UVT is cold and unenergized. The output of QA1 is also cold. The undervoltage tripping control of QA1 is intelligently controlled by the first control unit on the single board, greatly improving product reliability and long-term operational stability, and eliminating safety hazards.

[0038] Figure 2 This is the connection circuit diagram for the undervoltage circuit breaker on the generator side. It includes the second power supply switch QF8, the first control unit GP1, the third control unit GP3, and the second transfer switch SA2. Its overall structure is basically the same as the connection circuit of the undervoltage circuit breaker on the mains side. The difference is that the second power supply switch QF8 is connected to the generator output terminal, and the generator-side undervoltage circuit breaker (second undervoltage circuit breaker QA2) replaces the... Figure 1 The undervoltage circuit breaker on the central power side (first undervoltage circuit breaker QA1) was replaced by the third control unit GP3. Figure 1 The position of the second control unit GP2 is replaced by the second changeover switch SA2. Figure 1 The position of the first changeover switch SA1 is such that the normally closed auxiliary contact of the first undervoltage circuit breaker QA1 (mains-side undervoltage circuit breaker) is connected in series in the undervoltage monitoring power supply circuit of the second undervoltage circuit breaker QA2 (generator-side undervoltage circuit breaker). Its initial state and intelligent control state are analogous to the operation on the mains side and will not be elaborated further here.

[0039] In summary, the parallel and off-grid control circuit of the embodiment introduces a multi-contact position change-over switch, controls the units of the power side circuit breaker or the oil machine side circuit breaker and the single board control unit by the multi-position change-over switch, and changes the power supply mode of the power side circuit breaker or the oil machine side circuit breaker through a group of normally closed contacts in the series change-over switch, so that the normally closed contacts of the change-over switch are switched to the normally open state when the single board control unit is changed, and then the output end of the under-voltage circuit breaker is in a cold state and does not carry current for a long time before the parallel and off-grid control mode is switched, so that the overall work is safer and more reliable.

[0040] In addition, by connecting the normally closed auxiliary contact of the oil machine side under-voltage circuit breaker in series to the under-voltage monitoring power supply circuit of the power side under-voltage circuit breaker and connecting the normally closed auxiliary contact of the power side under-voltage circuit breaker in series to the under-voltage monitoring power supply circuit of the oil machine side under-voltage circuit breaker, the electrical interlocking of the power side under-voltage circuit breaker and the oil machine side under-voltage circuit breaker is formed, so that they will not be closed at the same time during the under-voltage monitoring control process, and the working safety and reliability of the circuit breaker control unit during control can still be ensured.

[0041] Embodiment 2:

[0042] In particular, the application also provides a parallel and off-grid control cabinet comprising the parallel and off-grid control circuit as described above.

[0043] The above embodiments are only for illustrating the technical concept and characteristics of the utility model, and the purpose is to enable persons skilled in the art to understand the content of the utility model and implement it, and it cannot limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit and essence of the utility model should be covered within the protection scope of the utility model.

Claims

1. A grid-connected / off-grid control circuit for controlling the generator and mains power to operate in parallel or on-grid mode, characterized in that, The grid connection and off-grid control circuit includes a power supply switch, a first control unit, a second control unit, a transfer switch, a first undervoltage circuit breaker, and a second undervoltage circuit breaker, wherein: The power supply switch is connected to the output terminal of the mains power supply or the generator; The changeover switch includes a first normally open contact, a second normally open contact, a first normally closed contact, a second normally closed contact, and a third normally closed contact; The control terminal of the first control unit is connected to the induction coil in the first undervoltage circuit breaker via the first normally open contact and the second normally open contact. The power input terminal of the second control unit is connected in series with the third normally closed contact and the power supply switch to form an undervoltage monitoring power supply circuit. The output terminal of the second control unit is connected to the induction coil via the first normally closed contact and the second normally closed contact. The normally closed auxiliary contact of the second undervoltage circuit breaker is connected in series in the undervoltage monitoring power supply circuit; One of the first undervoltage circuit breaker and the second undervoltage circuit breaker is an undervoltage circuit breaker on the generator side, and the other is an undervoltage circuit breaker on the mains power side.

2. The grid-connected / off-grid control circuit according to claim 1, characterized in that, The power supply switch includes two connection terminals, namely a first connection terminal and a second connection terminal. The first connection terminal is connected in series with the normally closed contact of the second undervoltage circuit breaker and then connected to one end of the third normally closed contact. The other end of the third normally closed contact is connected to one power input terminal of the second control unit, and the other power input terminal of the second control unit is connected to the second connection terminal.

3. The grid-connected / off-grid control circuit according to claim 2, characterized in that, The positive and negative terminals of the mains power or generator output are respectively connected to the first connection terminal or the second connection terminal.

4. The grid-connected / off-grid control circuit according to claim 1, characterized in that, The closing mechanism of the first undervoltage circuit breaker is connected to the power supply switch, and several loads are connected on the connection line between the closing mechanism and the power supply switch.

5. The grid-connected / off-grid control circuit according to claim 1, characterized in that, The indicator light of the first undervoltage circuit breaker is connected to the power supply switch.

6. A grid-connected / off-grid control cabinet, characterized in that, Includes the on-grid / off-grid control circuit as described in any one of claims 1 to 5.

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