A microcomputer protection device high-voltage bus isolation module

Abstract

The utility model discloses a kind of microcomputer protection device high-voltage bus isolation module, comprising: high-voltage bus and ground wire;First channel output end;Second channel output end;First high-side optocoupler solid-state relay;First low-side optocoupler solid-state relay;Second high-side optocoupler solid-state relay;Second low-side optocoupler solid-state relay, its input end is connected to second channel output end, output end is connected to ground wire;Current detection shunt resistance, set between the common backflow point of first low-side optocoupler solid-state relay and second low-side optocoupler solid-state relay and ground wire;Filter circuit, parallelly connected with current detection shunt resistance.The utility model has following beneficial effects: through the unique H bridge type optocoupler structure and double-stage authorization interlock mechanism, high reliability power switching, high security isolation protection and high-precision current detection function are realized.

Description

Technical Field

[0001] This utility model relates to a high-voltage busbar isolation module for a microcomputer protection device, and in particular to a dual-channel structure for safety isolation and control of high-voltage DC power supply in a power system protection device. Background Technology

[0002] With the development of intelligent power systems, microprocessor-based protection devices are being used more and more widely in power grids. As a crucial guarantee for the safe operation of power systems, the high-voltage control section of these devices requires reliable isolation modules to achieve power control and fault protection functions. Currently, the following isolation technology solutions are mainly available on the market:

[0003] Traditional mechanical relays were the earliest technology used, controlling circuit on / off states through the physical opening and closing of mechanical contacts. While mechanical relays are simple in structure and offer good electrical isolation, they suffer from several serious drawbacks: First, frequent operation of the mechanical contacts leads to contact wear, limiting the switch's lifespan to typically only 10 years. 5 -10 6 Firstly, mechanical relays have a limited lifespan; secondly, they are prone to arcing when disconnecting high-voltage power, causing contact erosion and greatly shortening their lifespan; thirdly, the slow response speed of mechanical structures makes it difficult to meet the time requirements of modern microcomputer protection devices for rapid disconnection; and finally, mechanical relays have a mechanical rebound phenomenon, which can lead to unstable instantaneous circuit switching and introduce electrical interference.

[0004] Transistor switching solutions replace mechanical contacts with transistors (such as MOSFETs and IGBTs), overcoming some of the shortcomings of mechanical relays. These solutions offer fast response times and eliminate mechanical wear issues, but their isolation performance is insufficient. In the 400V high-voltage environment of microprocessor-based protection devices, a high degree of isolation is required between the control circuit and the high-voltage section to ensure the safety of the control system, a requirement that ordinary transistor solutions struggle to meet. While isolation can be achieved by combining opto-isolators with drive circuits, this combination is complex, costly, and prone to introducing timing mismatches between components.

[0005] Integrated H-bridge drive solutions use integrated H-bridge driver chips to control power MOSFETs / IGBTs, offering advantages such as compact structure and strong drive capability. However, this type of solution still has several significant problems: First, the isolation withstand voltage of integrated driver chips is usually insufficient to cope with a 400V DC environment; second, the functions of integrated chips are fixed, limiting flexibility and making it difficult to optimize for different application scenarios; third, the integrated design means that a single point of failure can lead to the failure of the entire module.

[0006] Optoelectronic solid-state relays integrate an LED light source with a photosensitive semiconductor receiver, achieving electrical isolation and switching functions through optocoupler. This solution combines the excellent isolation of mechanical relays with the fast response characteristics of transistors. However, common single-device optoelectronic solid-state relays on the market have the following drawbacks: First, a single device cannot achieve bidirectional control of both high and low sides, resulting in significant functional limitations; second, they lack effective current monitoring methods, making overcurrent protection impossible; third, most products do not consider default safety mechanisms under fault conditions in their structural design, posing potential safety hazards.

[0007] In summary, existing isolation solutions for high-voltage applications of microprocessor-based protection devices generally suffer from problems such as complex structure, slow response speed, insufficient isolation performance, low reliability, and lack of effective current monitoring and safety assurance mechanisms. Therefore, there is an urgent need to develop a high-voltage busbar isolation module with high reliability, high safety, fast response, simple structure, and current detection capabilities to meet the stringent requirements of modern microprocessor-based protection devices. Utility Model Content

[0008] The purpose of this invention is to provide a high-voltage busbar isolation module for a microcomputer-based protection device. This high-voltage busbar isolation module features a simple structure, fast response speed, excellent isolation performance, high safety and reliability, and precise current monitoring capabilities.

[0009] The above-mentioned technical objective of this utility model is achieved through the following technical solution: A high-voltage busbar isolation module for a microcomputer protection device, comprising: a high-voltage busbar (400) and a ground wire (0); a first channel output terminal (OUT1); a second channel output terminal (OUT2); a first high-side optocoupler solid-state relay (Q3), whose input terminal is connected to the high-voltage busbar (400) and whose output terminal is connected to the first channel output terminal (OUT1); a first low-side optocoupler solid-state relay (Q4), whose input terminal is connected to the first channel output terminal (OUT1) and whose output terminal is connected to the ground wire (0); a second high-side optocoupler... A solid-state relay (Q5) has its input terminal connected to the high-voltage bus (400) and its output terminal connected to the second channel output terminal (OUT2); a second low-side optocoupler solid-state relay (Q6) has its input terminal connected to the second channel output terminal (OUT2) and its output terminal connected to the ground wire (0); a current-sensing shunt resistor (R65) is disposed between the common return point of the first low-side optocoupler solid-state relay (Q4) and the second low-side optocoupler solid-state relay (Q6) and the ground wire (0); and a filter circuit (R66, C42) is connected in parallel with the current-sensing shunt resistor (R65).

[0010] The present invention is further configured to include: a first high-side control line (D) for controlling the LED anode of the first high-side optocoupler solid-state relay (Q3); a first low-side control line (C) for controlling the LED anode of the first low-side optocoupler solid-state relay (Q4); a second high-side control line (F) for controlling the LED anode of the second high-side optocoupler solid-state relay (Q5); and a second low-side control line (E) for controlling the LED anode of the second low-side optocoupler solid-state relay (Q6).

[0011] The present invention is further configured to include: a first common enable line (H2) connected to the LED cathode of the first high-side optocoupler solid-state relay (Q3); a second common enable line (H1) connected to the LED cathode of the second high-side optocoupler solid-state relay (Q5); the first high-side control line (D) and the first common enable line (H2) together constitute a hardware secondary authorization interlock structure; the second high-side control line (F) and the second common enable line (H1) together constitute a hardware secondary authorization interlock structure.

[0012] The present invention is further configured to include: a first high-side current-limiting resistor (R26), connected in series between the first high-side control line (D) and the LED anode of the first high-side optocoupler solid-state relay (Q3); a first low-side current-limiting resistor (R25), connected in series between the first low-side control line (C) and the LED anode of the first low-side optocoupler solid-state relay (Q4); a second high-side current-limiting resistor (R23), connected in series between the second high-side control line (F) and the LED anode of the second high-side optocoupler solid-state relay (Q5); and a second low-side current-limiting resistor (R24), connected in series between the second low-side control line (E) and the LED anode of the second low-side optocoupler solid-state relay (Q6).

[0013] The present invention is further configured to include: a first high-side pull-down resistor (R28) connected between the first common enable line (H2) and ground; a second high-side pull-down resistor (R27) connected between the second common enable line (H1) and ground; a first low-side pull-down resistor (R29) connected between the LED cathode of the first low-side optocoupler solid-state relay (Q4) and ground; and a second low-side pull-down resistor (R30) connected between the LED cathode of the second low-side optocoupler solid-state relay (Q6) and ground.

[0014] The present invention is further configured such that: the filter circuit includes a filter resistor (R66) and a filter capacitor (C42) connected in series and then connected in parallel with the current detection shunt resistor (R65); the connection point of the filter circuit is provided with a reserved measurement point (O1) for connecting external detection or protection equipment.

[0015] The present invention is further configured such that: the first high-side optocoupler solid-state relay (Q3), the first low-side optocoupler solid-state relay (Q4), the second high-side optocoupler solid-state relay (Q5) and the second low-side optocoupler solid-state relay (Q6) are all bidirectional optical MOS switching devices, capable of withstanding bipolar surges.

[0016] The present invention is further configured such that: the first channel output terminal (OUT1) can achieve three working states of being connected to high potential, grounded, or floating by controlling the on / off state of the first high-side optocoupler solid-state relay (Q3) and the first low-side optocoupler solid-state relay (Q4); the second channel output terminal (OUT2) can achieve three working states of being connected to high potential, grounded, or floating by controlling the on / off state of the second high-side optocoupler solid-state relay (Q5) and the second low-side optocoupler solid-state relay (Q6).

[0017] The present invention is further configured such that the first high-side pull-down resistor (R28), the second high-side pull-down resistor (R27), the first low-side pull-down resistor (R29), and the second low-side pull-down resistor (R30) are configured such that when the control signal is missing or the connection is broken, the LEDs of each optocoupler solid-state relay are not turned on, and the module enters the default safe shutdown state.

[0018] In summary, this utility model has the following beneficial effects: 1. Highly Integrated and Optimized Structure: Through an H-bridge discrete optocoupler structure design, four independent optocoupler solid-state relays (Q3, Q4, Q5, Q6) are arranged into two independent control channels (OUT1, OUT2), enabling the module to achieve complete high- and low-side bidirectional control functions within a small footprint. In particular, the spatial layout combining vertical layering and horizontal partitioning makes the current path direct and clear, reducing parasitic inductance and resistance, and improving switching efficiency. Simultaneously, the low-side loops of the two channels adopt a Y-type convergence structure to connect to a common shunt point, achieving resource sharing of detection while ensuring functional independence, significantly simplifying structural complexity.

[0019] 2. High-Reliability Contactless Switching: Utilizing optocoupler solid-state relays instead of traditional mechanical relays completely eliminates mechanical contact wear and springback issues. Structurally, there are no moving mechanical parts, avoiding the risk of mechanical fatigue failure and improving switch lifespan. Simultaneously, the optocoupler switching method shortens response time, significantly improving protection action speed and enhancing system safety.

[0020] 3. Safety Assurance Mechanism: The module employs a multi-layered structural design to ensure safety and reliability. First, the optocoupler solid-state relay uses an internal opto-isolation structure to provide isolation withstand voltage, effectively isolating the high-voltage side from the control side. Second, a hardware-level secondary authorization interlocking mechanism is formed through a dual control structure of anode command and cathode enable, structurally preventing misoperation. All control lines are equipped with pull-down resistors (R27, R28, R29, R30) to ensure that the module automatically returns to the safe shutdown state when the control signal is missing, conforming to the safety principle of "safety upon power failure." Finally, a dual-channel shared shunt detection structure enables current monitoring, providing a foundation for overcurrent protection.

[0021] 4. Functional Configuration Capabilities: Each output channel (OUT1, OUT2) can achieve three operating states—high potential, grounded, or floating—by controlling the corresponding high-side and low-side optocoupler solid-state relay combinations, meeting the needs of different application scenarios. The two channels can be controlled independently, supporting complementary, alternating, or synchronous control modes, expanding the product's applicability. Simultaneously, the reserved measurement point (O1) facilitates the connection of external detection or protection equipment, enhancing system scalability.

[0022] 5. Optimized Current Detection Structure: The module adopts a centralized shunt design, with a single shunt resistor (R65) located at the common return point on the low side of both channels. This reduces the number of detection components, simplifies the circuit structure, and ensures consistent detection accuracy. The filter network (R66 / C42) effectively filters out switching spike interference, making current monitoring more accurate and reliable while retaining millisecond-level fast response capability, providing a foundation for the system to achieve precise overcurrent protection. Attached Figure Description

[0023] Figure 1 This is a structural schematic diagram of the high-voltage busbar isolation module of the microcomputer protection device of this utility model. Detailed Implementation

[0024] The present invention will now be described in further detail with reference to the accompanying drawings.

[0025] like Figure 1 As shown, this utility model discloses a high-voltage busbar isolation module for a microcomputer protection device. It adopts an H-bridge structure and consists of a dual-channel isolation system composed of four optocoupler solid-state relays. The module includes a high-voltage busbar (400) and a ground wire (0), located at the top and bottom of the module respectively, forming a power input path.

[0026] The module includes a first channel output terminal (OUT1) and a second channel output terminal (OUT2), located in the central area of ​​the module, for outputting control signals or power. A first high-side optocoupler solid-state relay (Q3) is positioned between the high-voltage bus (400) and the first channel output terminal (OUT1), with its input terminal (pin 5) connected to the high-voltage bus (400) and its output terminal (pin 4) connected to the first channel output terminal (OUT1). A first low-side optocoupler solid-state relay (Q4) is positioned between the first channel output terminal (OUT1) and the ground wire (0), with its input terminal (pin 5) connected to the first channel output terminal (OUT1) and its output terminal (pin 4) connected to a common return point.

[0027] Similarly, the second high-side optocoupler solid-state relay (Q5) is disposed between the high-voltage bus (400) and the second channel output terminal (OUT2), with its input terminal connected to the high-voltage bus (400) and its output terminal connected to the second channel output terminal (OUT2). The second low-side optocoupler solid-state relay (Q6) is disposed between the second channel output terminal (OUT2) and the ground wire (0), with its input terminal connected to the second channel output terminal (OUT2) and its output terminal connected to the same common return point.

[0028] A current-sensing shunt resistor (R65) is positioned between the common return point of the first low-side optocoupler solid-state relay (Q4) and the second low-side optocoupler solid-state relay (Q6) and the ground wire (0), forming a T-shaped structure for detecting the total current flowing through the two channels. A filter circuit is connected in parallel with the current-sensing shunt resistor (R65), including a series-connected filter resistor (R66) and a filter capacitor (C42), to filter out transient interference from switching and improve current detection accuracy.

[0029] Each optocoupler solid-state relay uses a standard 6-pin package, typically measuring approximately 8×5×2mm. Its internal structure includes an LED light-emitting area and a bidirectional MOS receiving area, with complete electrical isolation between the two parts. All four optocoupler solid-state relays are bidirectional opto-MOS switching devices, capable of withstanding bipolar surges and improving the system's anti-interference capability.

[0030] The module also includes a control signal input structure. A first high-side control line (D) is connected to the LED anode of a first high-side optocoupler solid-state relay (Q3) via a first high-side current-limiting resistor (R26) to control its on-state. A first low-side control line (C) is connected to the LED anode of a first low-side optocoupler solid-state relay (Q4) via a first low-side current-limiting resistor (R25). Similarly, a second high-side control line (F) is connected to the LED anode of a second high-side optocoupler solid-state relay (Q5) via a second high-side current-limiting resistor (R23), and a second low-side control line (E) is connected to the LED anode of a second low-side optocoupler solid-state relay (Q6) via a second low-side current-limiting resistor (R24).

[0031] To implement a hardware-level secondary authorization interlock mechanism, the module is configured with a first common enable line (H2) connected to the LED cathode of the first high-side optocoupler solid-state relay (Q3), and a second common enable line (H1) connected to the LED cathode of the second high-side optocoupler solid-state relay (Q5). This dual control structure of anode command and cathode enable ensures that the high-side optocoupler can only conduct when both the control signal and the enable signal are valid, effectively preventing the risk of misoperation.

[0032] To ensure power failure safety, the module is equipped with multiple pull-down resistors: the first high-side pull-down resistor (R28) is connected between the first common enable line (H2) and ground; the second high-side pull-down resistor (R27) is connected between the second common enable line (H1) and ground; the first low-side pull-down resistor (R29) is connected between the LED cathode of the first low-side optocoupler solid-state relay (Q4) and ground; and the second low-side pull-down resistor (R30) is connected between the LED cathode of the second low-side optocoupler solid-state relay (Q6) and ground. These pull-down resistors ensure that the LEDs of each optocoupler solid-state relay are not turned on when the control signal is missing or the connection is broken, and the module automatically enters the default safety shutdown state.

[0033] The filter circuit has a reserved measurement point (O1) at its connection point, facilitating the connection of external detection or protection equipment and forming a convenient mechanical interface. Through this interface, the current value can be easily monitored or an external protection circuit can be connected, further improving system safety.

[0034] In practical applications, the first channel output (OUT1) and the second channel output (OUT2) can be controlled by the corresponding high-side and low-side optocoupler solid-state relay combinations to achieve three working states: connected to high potential, grounded, or floating. For example, when the first high-side optocoupler solid-state relay (Q3) is on and the first low-side optocoupler solid-state relay (Q4) is off, the first channel output (OUT1) is connected to high potential; when the first high-side optocoupler solid-state relay (Q3) is off and the first low-side optocoupler solid-state relay (Q4) is on, the first channel output (OUT1) is grounded; when both the first high-side optocoupler solid-state relay (Q3) and the first low-side optocoupler solid-state relay (Q4) are off, the first channel output (OUT1) is floating. The control method for the second channel output (OUT2) is similar to that of the first channel.

[0035] This flexible control structure allows the module to adapt to different types of load requirements, supporting various application scenarios such as polarity reversal and dual-coil drive, significantly expanding the product's applicability. Simultaneously, the two channels can be controlled completely independently, achieving complementary, alternating, or synchronous operation to meet practical usage needs.

Claims

1. A high-voltage busbar isolation module for a microcomputer protection device, characterized in that, include: High-voltage busbar (400) and ground wire (0); First channel output (OUT1); Second channel output (OUT2); The first high-side optocoupler solid-state relay (Q3) has its input terminal connected to the high-voltage bus (400) and its output terminal connected to the first channel output terminal (OUT1). The first low-side optocoupler solid-state relay (Q4) has its input terminal connected to the first channel output terminal (OUT1) and its output terminal connected to the ground wire (0); The second high-side optocoupler solid-state relay (Q5) has its input terminal connected to the high-voltage bus (400) and its output terminal connected to the output terminal of the second channel (OUT2); The second low-side optocoupler solid-state relay (Q6) has its input terminal connected to the output terminal (OUT2) of the second channel and its output terminal connected to the ground wire (0); A current sensing shunt resistor (R65) is placed between the common return point of the first low-side optocoupler solid-state relay (Q4) and the second low-side optocoupler solid-state relay (Q6) and the ground wire (0); The filter circuit is connected in parallel with the current sensing shunt resistor (R65).

2. The high-voltage busbar isolation module according to claim 1, characterized in that, Also includes: The first high-side control line (D) is used to control the LED anode of the first high-side optocoupler solid-state relay (Q3); The first low-side control line (C) is used to control the LED anode of the first low-side optocoupler solid-state relay (Q4); The second high-side control line (F) is used to control the LED anode of the second high-side optocoupler solid-state relay (Q5); The second low-side control line (E) is used to control the LED anode of the second low-side optocoupler solid-state relay (Q6).

3. The high-voltage busbar isolation module according to claim 2, characterized in that, Also includes: The first common enable line (H2) is connected to the LED cathode of the first high-side optocoupler solid-state relay (Q3); The second common enable line (H1) is connected to the LED cathode of the second high-side optocoupler solid-state relay (Q5); The first high-side control line (D) and the first common enable line (H2) together constitute a hardware secondary authorization interlock structure; The second high-side control line (F) and the second common enable line (H1) together constitute a hardware secondary authorization interlock structure.

4. The high-voltage busbar isolation module according to claim 2, characterized in that, Also includes: The first high-side current-limiting resistor (R26) is connected in series between the first high-side control line (D) and the LED anode of the first high-side optocoupler solid-state relay (Q3); The first low-side current-limiting resistor (R25) is connected in series between the first low-side control line (C) and the LED anode of the first low-side optocoupler solid-state relay (Q4); The second high-side current-limiting resistor (R23) is connected in series between the second high-side control line (F) and the LED anode of the second high-side optocoupler solid-state relay (Q5); The second low-side current-limiting resistor (R24) is connected in series between the second low-side control line (E) and the LED anode of the second low-side optocoupler solid-state relay (Q6).

5. The high-voltage busbar isolation module according to claim 3, characterized in that, Also includes: The first high-side pull-down resistor (R28) is connected between the first common enable line (H2) and ground; The second high-side pull-down resistor (R27) is connected between the second common enable line (H1) and ground; The first low-side pull-down resistor (R29) is connected between the LED cathode of the first low-side optocoupler solid-state relay (Q4) and ground; The second low-side pull-down resistor (R30) is connected between the LED cathode of the second low-side optocoupler solid-state relay (Q6) and ground.

6. The high-voltage busbar isolation module according to claim 1, characterized in that: The filtering circuit includes a filter resistor (R66) and a filter capacitor (C42) connected in series and then connected in parallel with the current detection shunt resistor (R65); The connection point of the filter circuit is provided with a reserved measurement point (O1) for connecting external detection or protection equipment.

7. The high-voltage busbar isolation module according to claim 1, characterized in that: The first high-side optocoupler solid-state relay (Q3), the first low-side optocoupler solid-state relay (Q4), the second high-side optocoupler solid-state relay (Q5), and the second low-side optocoupler solid-state relay (Q6) are all bidirectional opto-MOS switching devices capable of withstanding bipolar surges.

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