High-voltage thyristor isolation temperature detection system

Abstract

The invention, which belongs to the technical field of power electronics, discloses a high-voltage thyristor isolation temperature detection system comprising a thyristor assembly connected with a wireless temperature sensor; the control system comprises a wireless receiving unit and a thyristor control unit; the wireless receiving system is respectively connected with the wireless temperature sensor and the thyristor control system; the isolation power supply assembly is connected with the wireless temperature sensor; a battery of the wireless temperature sensor is removed, and an external lead wire power supply mode is adopted. As long as an external power supply is powered on, the wireless temperature sensor can transmit data at a second-level speed, the safety isolation requirement of high voltage resistance is met, a magnetic isolation on-line power supply mode is adopted for power supply, data transmission at a higher speed can be achieved, the problem of too large power consumption is avoided, and the requirement for operation temperature detection of power electronic equipment with large dynamic changes is met.

Description

Technical Field

[0001] The invention relates to the technical field of power electronics, in particular to a high-voltage thyristor isolation temperature detection system. Background Art

[0002] In medium and high voltage motor soft starters, medium and high voltage power regulators, medium and high voltage solid state switches and other products, the thyristors in the thyristor assembly are key components. However, high voltage and high power thyristors are generally disc-type packages, and their heat sinks are installed by pressing the cathode and anode heat sinks. The heat sink not only dissipates heat, but is also a live body. When detecting the temperature of the heat sink, a safe isolation solution needs to be adopted.

[0003] Common temperature detection methods are divided into contact measurement and non-contact measurement. Common contactor measurement methods in the electronics field include: resistance detection method, thermocouple measurement method. Common non-contact measurement methods include: optical fiber detection method, infrared temperature measurement method, wireless temperature measurement method, and magnetic temperature measurement method.

[0004] The contact temperature measurement method will cause the temperature measuring device to carry strong electricity, and it is necessary to increase the isolation of the subsequent power supply. If the voltage of the strong power system is high, the power supply design becomes complicated. Therefore, it is common to use high-voltage resistant thermal insulation materials to seal the contact resistance so that the detection resistor is directly isolated from the strong power circuit. However, in the field of medium and high voltage, this method has great safety risks and is generally not adopted.

[0005] Non-contact measurement can solve the problem of isolating strong electricity from control electricity. However, solutions such as optical fiber detection and infrared detection greatly increase the cost of temperature detection. And because the thyristor string is often a closed device, the installation of optical fiber and infrared detectors is not only costly, but also requires a large installation space and is difficult to install, and the structural design requirements of the thyristor string are more prominent. Moreover, this detection method has large errors and is easily affected by the environment and light.

[0006] In the power system, a wireless temperature sensor is commonly used. The wireless temperature sensor is tied to the temperature measuring copper bar or the temperature measuring body in the form of a strap. It is small in size and easy to assemble. The sensor is powered by a built-in battery and transmits data at a low speed (generally transmitting data once every 10 seconds). It operates with low power consumption and can generally operate for 5 years without replacing the battery. For the power system, the temperature on the power transmission line changes slowly, and there is a regular power maintenance every year, so there is an opportunity to replace the battery without affecting the operation of the system. This method is suitable for equipment such as long-term stable power lines.

[0007] Used in power electronic thyristor components with rapid heat accumulation and rapid temperature changes, due to the rapid temperature change of the system (S level), the data transmission rate of the wireless sensor needs to be increased by at least 10 times compared with the commonly used method. This has led to the problem of increased power consumption of the sensor and a significant reduction in battery power supply time. For products with thyristor components, their loads often require continuous power supply or will not be shut down for maintenance. In addition, the thyristor string is often assembled in the casing, which is even more inconvenient to disassemble. Summary of the invention

[0008] In order to solve the problems of the prior art, the present invention provides a high-voltage thyristor isolation temperature detection system, comprising: a thyristor assembly, wherein the thyristor assembly is connected to a wireless temperature sensor;

[0009] A control system, the control system comprising a wireless receiving unit and a thyristor control unit;

[0010] The wireless receiving system is connected to the wireless temperature sensor and the thyristor control unit respectively;

[0011] An isolated power supply component is connected to the wireless temperature sensor.

[0012] Furthermore, the wireless temperature sensor is connected to a heat sink of the thyristor assembly.

[0013] Further, the thyristor assembly comprises: a plurality of thyristor strings connected in series;

[0014] The heat sink is connected between adjacent thyristor strings;

[0015] The wireless temperature sensor is connected to at least one of the heat sinks.

[0016] Further, the isolated power supply component includes: a power flyback circuit;

[0017] The power flyback circuit includes a transformer, the primary side of the transformer is connected to a flyback power primary circuit, and the flyback power primary circuit is connected to an external power supply; the secondary side of the transformer is connected to a power conversion power supply circuit, and the power conversion power supply circuit is connected to the wireless temperature sensor.

[0018] Furthermore, the primary circuit of the flyback power supply includes a MOS tube, the drain of the MOS tube is connected to the ground terminal of the primary side of the transformer, and the primary electrode of the MOS tube is grounded.

[0019] Furthermore, the flyback power supply primary circuit also includes a primary winding absorption circuit;

[0020] The primary winding absorption circuit comprises: a first resistor and a transient suppression diode;

[0021] One end of the first resistor is connected to the wire between the transformer and the external power supply, the other end of the first resistor is connected to one end of the transient suppression diode, and the other end of the transient suppression diode is connected to the wire between the transformer and the MOS tube.

[0022] Furthermore, the primary circuit of the flyback power supply further includes a first capacitor, one end of the first capacitor is connected to an external power supply, and the other end of the first capacitor is grounded.

[0023] Furthermore, the power conversion and power supply circuit includes a flyback power supply secondary side rectification circuit and a flyback power supply output conversion circuit;

[0024] The secondary side rectifier circuit of the flyback power supply is respectively connected to the secondary side of the transformer and the flyback power supply output conversion circuit;

[0025] The flyback power supply output conversion circuit is connected to the wireless temperature sensor.

[0026] Furthermore, the secondary side rectifier circuit of the flyback power supply includes: a diode and a second capacitor;

[0027] The anode of the diode is connected to one end of the secondary side of the transformer, the cathode of the diode is connected to one end of the second capacitor, the other end of the second capacitor is connected to the other end of the secondary side of the transformer, and the other end of the second capacitor is grounded.

[0028] Furthermore, the flyback power supply output conversion circuit includes a voltage stabilizing chip;

[0029] A first voltage regulator tube is connected in parallel to the second capacitor, and a second voltage regulator tube is connected in parallel to the first voltage regulator tube;

[0030] One end of the second voltage regulator tube is connected to a power supply, and the other end of the second voltage regulator tube is grounded;

[0031] A third capacitor is connected in parallel between the second voltage regulator tube and the first voltage regulator tube, and a resistor string is connected in parallel between the third capacitor and the first voltage regulator tube;

[0032] The resistor string comprises: a second resistor and a third resistor;

[0033] The second resistor and the third resistor are connected in series, one end of the second resistor is connected to one end of the first voltage regulator tube, and one end of the third resistor is connected to the other end of the first voltage regulator tube;

[0034] A voltage stabilizing chip is arranged between the second resistor and the first voltage stabilizing tube, and the voltage stabilizing chip is connected to the wire between the second resistor and the third resistor.

[0035] Beneficial effects of the present invention:

[0036] This application removes the battery of the wireless temperature sensor and adopts an external lead power supply method. As long as the external power supply is powered, the wireless temperature sensor can transmit data at a speed of seconds, meeting the safety isolation requirements of high-voltage withstand voltage. The power supply adopts a magnetically isolated online power supply method, which can achieve higher-speed data transmission without the problem of excessive power consumption, and meet the operating temperature detection of power electronic equipment with large dynamic changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A system block diagram of the high-voltage thyristor isolation temperature detection device provided by the present invention;

[0038] Figure 2 This is an isolated power supply circuit diagram of the high-voltage thyristor isolated temperature detection device provided by the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] See also Figure 1-2 , the present invention provides a high-voltage thyristor isolation temperature detection system, comprising: a thyristor assembly, the thyristor assembly being connected to a wireless temperature sensor;

[0041] A control system, the control system comprising a wireless receiving unit and a thyristor control unit;

[0042] The wireless receiving system is connected to the wireless temperature sensor and the thyristor control system respectively;

[0043] The thyristor assembly comprises: a plurality of thyristor strings connected in series;

[0044] A charged heat sink is connected between adjacent thyristor strings;

[0045] The wireless temperature sensor is connected to one of the radiators;

[0046] An isolated power supply component is connected to the wireless temperature sensor and is also connected to a driver of the thyristor.

[0047] Among them, the main invention of this application is to remove the battery of the wireless temperature sensor and adopt an external lead power supply method. As long as the external power supply is powered, the sensor can transmit data at a speed of seconds. However, in the thyristor string, how to provide a low-voltage power supply has become the key to solving the problem. Using the principle of thyristor chopping, a magnetically isolated low-voltage power supply is designed. When the thyristor is working, the power supply is powered and the temperature detection is effective. When the thyristor is not working, the power supply is powered off and the thyristor temperature is not detected. This method successfully solves the application of wireless sensor temperature in thyristor string systems, especially in medium and high voltage systems. Compared with optical fiber detection and infrared detection solutions, this method has no electrical connection in wireless transmission, meets the requirements of safety isolation, has a simple solution, low cost, and temperature detection continuously meets dynamic requirements.

[0048] In addition, in response to the insulation problem of the current thyristor string live body temperature detection, this application applies the wireless temperature detection device of the power system to thyristor equipment with fast temperature changes and no power outage maintenance (such as soft starters, power regulators, SVC, etc.), to solve the problem of the rapid transmission of the device temperature data. The rapid transmission of data requires a continuous and more powerful power supply, which requires solving the problem of isolated power supply. At the same time, considering the working characteristics of the thyristor, an isolated power supply component is generated using insulated cables and magnetic devices.

[0049] The isolated power supply component includes: a power flyback circuit;

[0050] The power flyback circuit includes a transformer T1, the primary side of the transformer T1 is connected to a flyback power primary circuit, the flyback power primary circuit is connected to an external power supply (+24V); the flyback power primary circuit is connected to the control coil, and the control coil is connected to the wireless temperature sensor;

[0051] The secondary side of the transformer T1 is connected to a power conversion power supply circuit, and the power conversion power supply circuit is connected to the wireless temperature sensor;

[0052] When the thyristor drive trigger is positive, the primary circuit of the flyback power supply stores energy, and when the thyristor drive trigger is 0, the primary circuit of the flyback power supply releases energy to the rectifier circuit of the secondary side of the flyback circuit.

[0053] The primary circuit of the flyback power supply includes a MOS transistor Q1 , a drain of the MOS transistor Q1 is connected to the ground terminal of the primary side of the transformer T1 , and a primary electrode of the MOS transistor Q1 is grounded.

[0054] The flyback power supply primary circuit also includes a primary winding absorption circuit;

[0055] The primary winding absorption circuit includes: a first resistor R1 and a transient suppression diode D1;

[0056] One end of the first resistor R1 is connected to the wire between the transformer T1 and the external power supply, the other end of the first resistor R1 is connected to one end of the transient suppression diode D1, and the other end of the transient suppression diode D1 is connected to the wire between the transformer T1 and the MOS tube Q1;

[0057] The flyback power supply primary circuit further includes a first capacitor C1, one end of the first capacitor C1 is connected to an external power supply, and the other end of the first capacitor C1 is grounded;

[0058] The power conversion and power supply circuit includes a flyback power supply secondary side rectification circuit and a flyback power supply output conversion circuit;

[0059] The secondary side rectifier circuit of the flyback power supply is respectively connected to the secondary side of the transformer T1 and the flyback power supply output conversion circuit;

[0060] The flyback power supply output conversion circuit is connected to the wireless temperature sensor;

[0061] The secondary side rectifier circuit of the flyback power supply includes: a diode D2 and a second capacitor C2;

[0062] The anode of the diode D2 is connected to one end of the secondary side of the transformer T1, the cathode of the diode D2 is connected to one end of the second capacitor C2, the other end of the second capacitor C2 is connected to the other end of the secondary side of the transformer T1, and the other end of the second capacitor C2 is grounded;

[0063] The flyback power supply output conversion circuit includes a voltage stabilizing chip LM317;

[0064] The second capacitor C2 is connected in parallel with a first voltage regulator tube Z1, and the first voltage regulator tube Z1 is connected in parallel with a second voltage regulator tube Z2;

[0065] One end of the second voltage regulator tube Z2 is connected to a power source, and the other end of the second voltage regulator tube Z2 is grounded;

[0066] A third capacitor C3 is connected in parallel between the second voltage regulator tube Z2 and the first voltage regulator tube Z1, and a resistor string is connected in parallel between the third capacitor C3 and the first voltage regulator tube Z1;

[0067] The resistor string includes: a second resistor R2 and a third resistor R3;

[0068] The second resistor R2 and the third resistor R3 are connected in series, one end of the second resistor R2 is connected to one end of the first voltage regulator tube Z1, and one end of the third resistor R3 is connected to the other end of the first voltage regulator tube Z1;

[0069] A voltage regulator chip LM317 is provided between the second resistor R2 and the first voltage regulator tube Z1 , and the voltage regulator chip LM317 is connected to the wire between the second resistor R2 and the third resistor R3 .

[0070] Among them, T1 in the figure is a transformer. In the high-voltage system, the primary side uses high-insulation grade cables to ensure the system withstands voltage. Its working principle is: +24V control power supply and T1 and Q1 form the primary circuit of the flyback power supply, and D1 and R1 are the primary winding absorption circuit. D2 to C2 are the rectifier circuits on the secondary side of the flyback circuit. LM317 is a voltage regulator chip, which is used to convert the flyback output power supply into a high-precision power supply VCC_1 to power the wireless temperature sensor. When the thyristor drive trigger is positive, T1 stores energy; when the drive is 0, T1 releases energy to the secondary side. In the figure, Z1 and Z2 are used to clamp the safe working voltage of the voltage regulator chip to ensure circuit reliability. R2 and R3 are voltage adjustment resistors of LM317. Therefore, the power supply is energized when the thyristor is triggered.

[0071] The specific process of temperature detection is as follows:

[0072] A. When the thyristor device is in the stopped state, there is no thyristor drive, the power supply of the temperature detection device is 0V and the thyristor temperature cannot be detected.

[0073] B. When the thyristor device starts to operate, the thyristor drive is issued. At this time, the temperature detection power supply starts to work in the flyback mode, and the wireless temperature sensor obtains a +5V voltage.

[0074] C. When the wireless sensor power supply is powered, its temperature signal is transmitted to the receiving end wirelessly. During operation, the temperature signal is sent once per second (or several seconds). If this thyristor device is a high-voltage soft starter, its operating time is often tens of seconds to 1 minute. The shorter the operating time, the faster the thyristor temperature rises.

[0075] D. The wireless signal receiver converts the wireless signal into a communication signal and sends it to the MCU. At this time, the MCU determines once a second whether the thyristor temperature is faulty in order to provide temperature protection.

[0076] E. Generally, when the device is in short-term operation, such as a high-voltage soft start device, it only runs for a dozen seconds. If the temperature is updated every second and still cannot meet the performance requirements, the heat sink model can be used to simulate the temperature rise and fall curves by linear interpolation.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high voltage thyristor isolation temperature detection system, characterized in that: include: A thyristor assembly, wherein the thyristor assembly is connected to a wireless temperature sensor; A control system, the control system comprising a wireless receiving unit and a thyristor control unit; The wireless receiving system is connected to the wireless temperature sensor and the thyristor control unit respectively; An isolated power supply component is connected to the wireless temperature sensor.

2. The high voltage thyristor isolation temperature detection system according to claim 1, characterized in that: The wireless temperature sensor is connected to the heat sink of the thyristor assembly.

3. The high voltage thyristor isolation temperature detection system according to claim 2, characterized in that: The thyristor assembly comprises: a plurality of thyristor strings connected in series; The heat sink is connected between adjacent thyristor strings; The wireless temperature sensor is connected to at least one of the heat sinks.

4. The high voltage thyristor isolation temperature detection system according to claim 1, characterized in that: The isolated power supply component includes: a power flyback circuit; The power flyback circuit includes a transformer, the primary side of the transformer is connected to a flyback power primary circuit, and the flyback power primary circuit is connected to an external power supply; the secondary side of the transformer is connected to a power conversion power supply circuit, and the power conversion power supply circuit is connected to the wireless temperature sensor.

5. The high voltage thyristor isolation temperature detection system according to claim 4, characterized in that: The primary circuit of the flyback power supply includes a MOS tube, the drain of the MOS tube is connected to the ground terminal of the primary side of the transformer, and the primary electrode of the MOS tube is grounded.

6. The high voltage thyristor isolation temperature detection system according to claim 4, characterized in that: The flyback power supply primary circuit also includes a primary winding absorption circuit; The primary winding absorption circuit comprises: a first resistor and a transient suppression diode; One end of the first resistor is connected to the wire between the transformer and the external power supply, the other end of the first resistor is connected to one end of the transient suppression diode, and the other end of the transient suppression diode is connected to the wire between the transformer and the MOS tube.

7. The high voltage thyristor isolation temperature detection system according to claim 4, characterized in that: The flyback power supply primary circuit further includes a first capacitor, one end of the first capacitor is connected to an external power supply, and the other end of the first capacitor is grounded.

8. The high voltage thyristor isolation temperature detection system according to claim 4, characterized in that: The power conversion and power supply circuit includes a flyback power supply secondary side rectification circuit and a flyback power supply output conversion circuit; The secondary side rectifier circuit of the flyback power supply is respectively connected to the secondary side of the transformer and the flyback power supply output conversion circuit; The flyback power supply output conversion circuit is connected to the wireless temperature sensor.

9. The high-voltage thyristor isolation temperature detection system according to claim 8, characterized in that: The secondary side rectifier circuit of the flyback power supply includes: a diode and a second capacitor; The anode of the diode is connected to one end of the secondary side of the transformer, the cathode of the diode is connected to one end of the second capacitor, the other end of the second capacitor is connected to the other end of the secondary side of the transformer, and the other end of the second capacitor is grounded.

10. The high voltage thyristor isolation temperature detection system according to claim 9, characterized in that: The flyback power supply output conversion circuit includes a voltage stabilizing chip; A first voltage regulator tube is connected in parallel to the second capacitor, and a second voltage regulator tube is connected in parallel to the first voltage regulator tube; One end of the second voltage regulator tube is connected to a power supply, and the other end of the second voltage regulator tube is grounded; A third capacitor is connected in parallel between the second voltage regulator tube and the first voltage regulator tube, and a resistor string is connected in parallel between the third capacitor and the first voltage regulator tube; The resistor string comprises: a second resistor and a third resistor; The second resistor and the third resistor are connected in series, one end of the second resistor is connected to one end of the first voltage regulator tube, and one end of the third resistor is connected to the other end of the first voltage regulator tube; A voltage stabilizing chip is arranged between the second resistor and the first voltage stabilizing tube, and the voltage stabilizing chip is connected to the wire between the second resistor and the third resistor.

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