Switching signal isolation device for nuclear power emergency diesel generator set

Abstract

The utility model discloses a nuclear power emergency diesel generating set switch quantity signal isolation device relates to power generation equipment technical field, including DCDC power isolation module and a plurality of signal transmission channels, for any signal transmission channel, including safety level relay and photoelectric coupler isolation unit, and all signal transmission channels in photoelectric coupler isolation unit are integrated in photoelectric isolation device, the DCDC power isolation module, safety level relay and photoelectric isolation device all set up in safety level control cabinet, the safety level relay receives safety level switch quantity signal, and according to safety level switch quantity signal control photoelectric coupler isolation unit to set up in non -safety level control cabinet signal input device output non -safety level switch quantity signal, to realize safety level switch quantity signal and non -safety level switch quantity signal's isolation. The device can prevent the electromagnetic / radio frequency interference in non -safety level control cabinet through cable conduction to safety level control cabinet.

Description

Technical Field

[0001] This utility model relates to the field of power generation equipment technology, and in particular to a switching signal isolation device for nuclear power emergency diesel generator sets. Background Technology

[0002] The control system of a nuclear power plant's emergency diesel generator set typically includes a safety-grade control cabinet and a non-safety-grade control cabinet. The safety-grade control cabinet implements functions related to emergency operation and protection of the unit, while the non-safety-grade control cabinet implements functions related to non-emergency operation and protection, as well as alarm and display functions. Inevitably, there will be exchange of switching signals between the safety-grade and non-safety-grade control cabinets. To prevent faults in non-safety-grade signals from interfering with safety-grade functions, switching signal isolation is usually required on the safety-grade control cabinet side.

[0003] Traditional nuclear power emergency diesel generator sets typically use only safety-grade relays as isolation devices for switching signals, with relay contact signals directly output to the non-safety-grade control cabinet. The disadvantage is that electrical signal coupling between the safety-grade and non-safety-grade control cabinets via cables allows electromagnetic and radio frequency interference from the non-safety-grade control cabinet to be conducted to the safety-grade control cabinet, thus hindering its safety functions. Furthermore, if the safety-grade relay encounters an external transient voltage surge (such as electrostatic discharge or a switching surge), the relay coil may be damaged, and faults on the non-safety-grade side may propagate to the safety-grade side through the power supply circuit, affecting the reliability of the safety-grade control cabinet. Utility Model Content

[0004] In response to the aforementioned problems and technical requirements, the applicant has proposed a switching signal isolation device for nuclear power emergency diesel generator sets.

[0005] The technical solution of this utility model is as follows:

[0006] A switching signal isolation device for nuclear power emergency diesel generator sets includes a DC / DC power isolation module and several signal transmission channels. Each signal transmission channel includes a safety-grade relay and an optocoupler isolation unit. The auxiliary contacts of the safety-grade relay are adapted and connected to the optocoupler isolation unit. All optocoupler isolation units in all signal transmission channels are integrated into the optocoupler isolation device. The DC / DC power isolation module, safety-grade relay, and optocoupler isolation device are all housed in a safety-grade control cabinet. The DC / DC power isolation module supplies power to the optocoupler isolation device.

[0007] For any signal transmission channel, the safety-grade relay is used to receive safety-grade switching signals and control the optocoupler isolation unit to output non-safety-grade switching signals to the signal input device located in the non-safety-grade control cabinet according to the safety-grade switching signals, so as to achieve isolation between safety-grade switching signals and non-safety-grade switching signals.

[0008] A further technical solution is that one end of the safety-grade relay coil is connected to the negative input terminal of the DC / DC power isolation module, the positive input terminal of the DC / DC power isolation module is connected to the first signal input terminal of the safety-grade relay, and the other end of the safety-grade relay coil is connected to the second signal input terminal of the safety-grade relay. The first signal input terminal and the second signal input terminal are used to receive safety-grade switching signals.

[0009] A further technical solution is that the signal transmission channel also includes a TVS diode for protecting against transient surge voltages, and the TVS diode is connected in parallel across the two ends of the safety-grade relay coil.

[0010] A further technical solution is that the positive terminal of the primary-side light-emitting diode of the optocoupler isolation unit is connected to the positive output terminal of the DC / DC power isolation module, one end of the auxiliary contact of the safety-grade relay is connected to the negative output terminal of the DC / DC power isolation module, and the other end of the auxiliary contact of the safety-grade relay is connected to the negative terminal of the primary-side light-emitting diode of the optocoupler isolation unit.

[0011] A further technical solution is that the signal input device includes several signal input terminal groups, and the signal transmission channel corresponds one-to-one with the signal input terminal group;

[0012] For any signal transmission channel, the collector of the phototransistor on the secondary side of the optocoupler isolation unit in the signal transmission channel is connected to the positive input terminal of the corresponding signal input terminal group, and the emitter of the phototransistor on the secondary side of the optocoupler isolation unit in the signal transmission channel is connected to the negative input terminal of the corresponding signal input terminal group.

[0013] A further technical solution is that the auxiliary contact of the safety-grade relay is a normally open contact. When the safety-grade switching signal is logic "1", the coil of the safety-grade relay is energized, causing the auxiliary contact of the safety-grade relay to close; when the safety-grade switching signal is logic "0", the coil of the safety-grade relay is de-energized, causing the auxiliary contact of the safety-grade relay to open.

[0014] When the auxiliary contact of the safety-grade relay is closed, the optocoupler isolation unit outputs a non-safety-grade switching signal with a logic state of logic "1" to the signal input device; when the auxiliary contact of the safety-grade relay is open, the optocoupler isolation unit outputs a non-safety-grade switching signal with a logic state of logic "0" to the signal input device.

[0015] A further technical solution is that the opto-isolation device is kept separated from the equipment installed in the safety-grade control cabinet in both the vertical and horizontal directions.

[0016] A further technical solution is that the DC / DC power isolation module includes an input signal filtering unit, an anti-reverse current unit, a freewheeling and high-frequency switching excitation unit, an electromagnetic isolation unit, and an output signal filtering unit, wherein...

[0017] The input signal filtering unit includes an inductor L1 and a capacitor C1; the anti-reverse current unit includes a diode D1 and a diode D3; the freewheeling and high-frequency switching excitation unit includes a diode D2, a resistor R1, and an NMOS transistor Q1; the electromagnetic isolation unit includes a transformer T1; and the output signal filtering unit includes an inductor L2, a capacitor C2, and a capacitor C3.

[0018] A further technical solution is as follows: one end of the inductor L1 is connected to the negative terminal of the diode D1 and one end of the capacitor C1; the positive terminal of the diode D1 is connected to the positive input terminal of the DC / DC power isolation module; the other end of the capacitor C1 is connected to the negative input terminal of the DC / DC power isolation module; the other end of the inductor L1 is connected to one end of the resistor R1 and one end of the primary side of the transformer T1; the other end of the resistor R1 is connected to the negative terminal of the diode D2; the positive terminal of the diode D2 is connected to the other end of the primary side of the transformer and the drain of the NMOS transistor Q1; the source of the NMOS transistor Q1 is connected to the negative input terminal of the DC / DC power isolation module and connected to the first ground potential GND1.

[0019] A further technical solution is as follows: one end of the secondary side of transformer T1 is connected to the positive terminal of diode D3, the other end of the secondary side of transformer T1 is connected to the negative output terminal of DC / DC power isolation module, the negative terminal of diode D3 is connected to one end of inductor L2 and one end of capacitor C2, the other end of inductor L2 is connected to one end of capacitor C3 and the positive output terminal of DC / DC power isolation module, and the other ends of capacitors C2 and C3 are connected to the negative output terminal of DC / DC power isolation module and connected to the second ground potential GND2.

[0020] The beneficial technical effects of this utility model are:

[0021] This utility model provides a nuclear power emergency diesel generator set switch signal isolation device. It uses a safety-grade relay as the signal isolation boundary and employs an opto-isolation device for electro-optical-electrical signal conversion and isolation. This prevents electromagnetic and radio frequency interference from non-safety-grade control cabinets from being conducted to the safety-grade control cabinet via cables. Simultaneously, a TVS diode is connected in parallel across the safety-grade relay coil to protect it from damage by external transient voltage surges. Furthermore, a DC / DC power isolation module isolates the safety-grade power supply before powering the opto-isolation device, preventing faults from the non-safety-grade side from propagating through the power circuit and improving the reliability of the safety-grade control cabinet. Attached Figure Description

[0022] Figure 1 This is a structural block diagram of one embodiment of the nuclear power emergency diesel generator set switch signal isolation device provided by this utility model.

[0023] Figure 2 This is a circuit schematic diagram of one embodiment of the DC / DC power isolation module provided by this utility model. Detailed Implementation

[0024] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0025] This utility model provides a switching signal isolation device for nuclear power emergency diesel generator sets. The device includes a DC / DC power isolation module and several signal transmission channels. Each signal transmission channel includes a safety-grade relay and an optocoupler isolation unit. The auxiliary contacts of the safety-grade relay are adapted and connected to the optocoupler isolation unit. All optocoupler isolation units in all signal transmission channels are integrated into the optocoupler isolation device. The DC / DC power isolation module, safety-grade relay, and optocoupler isolation device are all housed in a safety-grade control cabinet. The DC / DC power isolation module supplies power to the optocoupler isolation device.

[0026] For any signal transmission channel, the safety-grade relay receives a safety-grade switching signal and controls the optocoupler isolation unit to output a non-safety-grade switching signal to the signal input device located in the non-safety-grade control cabinet based on the safety-grade switching signal. This switching signal isolation device uses the safety-grade relay as the electrical isolation boundary between the safety-grade and non-safety-grade switching signals, and performs opto-decoupling through an opto-isolation device, thus achieving isolation between the safety-grade and non-safety-grade switching signals. This effectively improves the reliability of switching signal transmission and can effectively prevent the spread of faults between devices, making it widely applicable to diesel generator sets used in nuclear power plants.

[0027] Please refer to Figure 1 This embodiment has two signal transmission channels. In practice, the number of signal transmission channels can be flexibly set according to application needs. Taking one signal transmission channel as an example, one end of the safety-grade relay coil is connected to the negative input terminal of the DC / DC power isolation module, the positive input terminal of the DC / DC power isolation module is connected to the first signal input terminal of the safety-grade relay, and the other end of the safety-grade relay coil is connected to the second signal input terminal of the safety-grade relay. The first and second signal input terminals are used to receive safety-grade switching signals (i.e.,...). Figure 1 The control signal shown is shown in Figure 1 / 2. In specific implementation, the specific input form of the safety-level switching signal can be consistent with the prior art. The positive terminal (IN1+) of the primary-side light-emitting diode of the optocoupler isolation unit is connected to the positive output terminal of the DC / DC power isolation module. One end of the auxiliary contact of the safety-level relay is connected to the negative output terminal of the DC / DC power isolation module, and the other end of the auxiliary contact of the safety-level relay is connected to the negative terminal (IN1-) of the primary-side light-emitting diode of the optocoupler isolation unit (not shown in the figure). The signal input device includes several signal input terminal groups. The signal transmission channel corresponds one-to-one with the signal input terminal group. In the signal transmission channel, the collector (OT1+) of the secondary-side phototransistor of the optocoupler isolation unit is connected to the positive input terminal (IN11+) of the corresponding signal input terminal group, and the emitter (OT1-) of the secondary-side phototransistor of the optocoupler isolation unit is connected to the negative input terminal (IN11-) of the corresponding signal input terminal group.

[0028] The auxiliary contact of the safety-grade relay is a normally open contact. The specific working principle of the device is as follows: when the safety-grade switching signal is logic "1", the first signal input terminal and the second signal input terminal are electrically connected, the coil of the safety-grade relay is energized, and the auxiliary contact of the safety-grade relay is closed; when the auxiliary contact of the safety-grade relay is closed, the primary-side light-emitting diode in the optocoupler isolation unit connected to it emits light, and the secondary-side phototransistor conducts, so that the optocoupler isolation unit outputs a non-safety-grade switching signal with a logic state of logic "1" to the signal input device;

[0029] When the safety-level switch signal is logic "0", the first signal input terminal and the second signal input terminal are disconnected, the safety-level relay coil is de-energized, and the auxiliary contact of the safety-level relay is opened. When the auxiliary contact of the safety-level relay is open, the primary-side light-emitting diode in the connected optocoupler isolation unit is turned off, causing the secondary-side phototransistor to turn off. Thus, the optocoupler isolation unit outputs a non-safety-level switch signal with a logic state of logic "0" to the signal input device. After receiving the non-safety-level switch signal, the signal input device performs logical operations, signal display, alarm functions, etc., based on the non-safety-level switch signal. The specific form of the signal input device can be consistent with existing technology.

[0030] Furthermore, the signal transmission channel also includes a TVS diode for protection against transient voltage surges, the TVS diode being connected in parallel across the coil of the safety-grade relay. When encountering an external transient voltage surge, the TVS diode can protect the safety-grade relay from damage.

[0031] Furthermore, the opto-isolation device within the safety-grade control cabinet must be kept vertically and horizontally separated from other equipment (DC / DC power isolation modules, safety-grade relays, etc.) located within the safety-grade control cabinet. Specifically, according to GB / T 13286-2021 "Independence Criteria for Safety-Grade Electrical Equipment and Circuits in Nuclear Power Plants," the minimum horizontal separation distance is 2.5 cm, and the minimum vertical separation distance is 15 cm.

[0032] The DC / DC power isolation module isolates the safety-grade power and converts it into the power required by the opto-isolation device, thereby supplying power to the non-safety-grade opto-isolation device, which is also located in the safety-grade control cabinet, thus preventing faults on the non-safety-grade side from spreading through the power circuit.

[0033] Please refer to Figure 2 In one embodiment of this utility model, the DC / DC power isolation module includes an input signal filtering unit, an anti-reverse current unit, a freewheeling and high-frequency switching excitation unit, an electromagnetic isolation unit, and an output signal filtering unit, wherein...

[0034] The input signal filtering unit includes an inductor L1 and a capacitor C1; the anti-reverse current unit includes a diode D1 and a diode D3; the freewheeling and high-frequency switching excitation unit includes a diode D2, a resistor R1, and an NMOS transistor Q1; the electromagnetic isolation unit includes a transformer T1; and the output signal filtering unit includes an inductor L2, a capacitor C2, and a capacitor C3.

[0035] One end of the inductor L1 is connected to the negative terminal of the diode D1 and one end of the capacitor C1. The positive terminal of the diode D1 is connected to the positive input terminal of the DC / DC power isolation module. The other end of the capacitor C1 is connected to the negative input terminal of the DC / DC power isolation module. The other end of the inductor L1 is connected to one end of the resistor R1 and one end of the primary side of the transformer T1. The other end of the resistor R1 is connected to the negative terminal of the diode D2. The positive terminal of the diode D2 is connected to the other end of the primary side of the transformer and the drain of the NMOS transistor Q1. The source of the NMOS transistor Q1 is connected to the negative input terminal of the DC / DC power isolation module and connected to the first ground potential GND1.

[0036] One end of the secondary side of transformer T1 is connected to the positive terminal of diode D3, and the other end of the secondary side of transformer T1 is connected to the negative output terminal of DC / DC power isolation module. The negative terminal of diode D3 is connected to one end of inductor L2 and one end of capacitor C2. The other end of inductor L2 is connected to one end of capacitor C3 and the positive output terminal of DC / DC power isolation module. The other ends of capacitors C2 and C3 are connected to the negative output terminal of DC / DC power isolation module and connected to the second ground potential GND2.

[0037] The positive and negative input terminals of the DC / DC power isolation module are connected to the positive and negative terminals of the safety-grade power supply, respectively. The gate of the NMOS transistor Q1 is controlled by a PWM signal to turn it on and off. The output voltage of the DC / DC power isolation module can be controlled by controlling the duty cycle of the PWM signal. When the DC / DC power isolation module is working, the safety-grade power supply is input to the DC / DC power isolation module and filtered by the input signal filtering unit. When the NMOS transistor Q1 is turned on, the current flows through the inductor L1 to charge the primary side of the transformer T1. When the NMOS transistor Q1 is turned off, the current freewheels through the diode D2 and the resistor R1. The secondary side of the transformer T1 induces and generates the output voltage, providing isolation between the safety-grade power supply voltage and the output voltage. The output voltage is filtered by the output signal filtering unit and then output to the opto-isolation device.

[0038] In the description of this specification, the terms "an embodiment / mode," "example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example, which is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0039] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances; the use of terms such as "first" and "second" is for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Features specified with "first" or "second" may explicitly or implicitly include at least one of those features.

[0040] The above descriptions are merely preferred embodiments of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations that can be directly derived or conceived by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included within the protection scope of the present invention.

Claims

1. A switching signal isolation device for nuclear power emergency diesel generator sets, characterized in that, The system includes a DC / DC power isolation module and several signal transmission channels. Each signal transmission channel includes a safety-grade relay and an optocoupler isolation unit. The auxiliary contacts of the safety-grade relay are adapted and connected to the optocoupler isolation unit. All optocoupler isolation units in all signal transmission channels are integrated into the optocoupler isolation device. The DC / DC power isolation module, safety-grade relay, and optocoupler isolation device are all housed in a safety-grade control cabinet. The DC / DC power isolation module supplies power to the optocoupler isolation device. For any signal transmission channel, the safety-grade relay is used to receive safety-grade switching signals and control the optocoupler isolation unit to output non-safety-grade switching signals to the signal input device located in the non-safety-grade control cabinet according to the safety-grade switching signals, so as to achieve isolation between safety-grade switching signals and non-safety-grade switching signals.

2. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, One end of the safety-grade relay coil is connected to the negative input terminal of the DC / DC power isolation module, the positive input terminal of the DC / DC power isolation module is connected to the first signal input terminal of the safety-grade relay, and the other end of the safety-grade relay coil is connected to the second signal input terminal of the safety-grade relay. The first signal input terminal and the second signal input terminal are used to receive safety-grade switching signals.

3. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The signal transmission channel also includes a TVS diode for protection against transient surge voltages, which is connected in parallel across the coil of the safety-grade relay.

4. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The positive terminal of the primary-side LED of the optocoupler isolation unit is connected to the positive output terminal of the DC / DC power isolation module. One end of the auxiliary contact of the safety-grade relay is connected to the negative output terminal of the DC / DC power isolation module, and the other end of the auxiliary contact of the safety-grade relay is connected to the negative terminal of the primary-side LED of the optocoupler isolation unit.

5. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The signal input device includes several signal input terminal groups, and the signal transmission channel corresponds one-to-one with each of the signal input terminal groups; For any signal transmission channel, the collector of the phototransistor on the secondary side of the optocoupler isolation unit in the signal transmission channel is connected to the positive input terminal of the corresponding signal input terminal group, and the emitter of the phototransistor on the secondary side of the optocoupler isolation unit in the signal transmission channel is connected to the negative input terminal of the corresponding signal input terminal group.

6. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The auxiliary contact of the safety-grade relay is a normally open contact. When the safety-grade switching signal is logic "1", the coil of the safety-grade relay is energized, causing the auxiliary contact of the safety-grade relay to close; when the safety-grade switching signal is logic "0", the coil of the safety-grade relay is de-energized, causing the auxiliary contact of the safety-grade relay to open. When the auxiliary contact of the safety-grade relay is closed, the optocoupler isolation unit outputs a non-safety-grade switching signal with a logic state of logic "1" to the signal input device; when the auxiliary contact of the safety-grade relay is open, the optocoupler isolation unit outputs a non-safety-grade switching signal with a logic state of logic "0" to the signal input device.

7. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The opto-isolation device is kept vertically and horizontally separated from the equipment installed in the safety-grade control cabinet.

8. The nuclear power emergency diesel generator set switch signal isolation device according to claim 1, characterized in that, The DC / DC power isolation module includes an input signal filtering unit, a reverse current prevention unit, a freewheeling and high-frequency switching excitation unit, an electromagnetic isolation unit, and an output signal filtering unit. The input signal filtering unit includes an inductor L1 and a capacitor C1; the anti-reverse current unit includes a diode D1 and a diode D3; the freewheeling and high-frequency switching excitation unit includes a diode D2, a resistor R1, and an NMOS transistor Q1; the electromagnetic isolation unit includes a transformer T1; and the output signal filtering unit includes an inductor L2, a capacitor C2, and a capacitor C3.

9. The nuclear power emergency diesel generator set switch signal isolation device according to claim 8, characterized in that, One end of the inductor L1 is connected to the negative terminal of the diode D1 and one end of the capacitor C1. The positive terminal of the diode D1 is connected to the positive input terminal of the DC / DC power isolation module. The other end of the capacitor C1 is connected to the negative input terminal of the DC / DC power isolation module. The other end of the inductor L1 is connected to one end of the resistor R1 and one end of the primary side of the transformer T1. The other end of the resistor R1 is connected to the negative terminal of the diode D2. The positive terminal of the diode D2 is connected to the other end of the primary side of the transformer and the drain of the NMOS transistor Q1. The source of the NMOS transistor Q1 is connected to the negative input terminal of the DC / DC power isolation module and connected to the first ground potential GND1.

10. The nuclear power emergency diesel generator set switch signal isolation device according to claim 8, characterized in that, One end of the secondary side of transformer T1 is connected to the positive terminal of diode D3, and the other end of the secondary side of transformer T1 is connected to the negative output terminal of DC / DC power isolation module. The negative terminal of diode D3 is connected to one end of inductor L2 and one end of capacitor C2. The other end of inductor L2 is connected to one end of capacitor C3 and the positive output terminal of DC / DC power isolation module. The other ends of capacitors C2 and C3 are connected to the negative output terminal of DC / DC power isolation module and connected to the second ground potential GND2.

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