Automatic testing device for response time of over-temperature monitoring channel of reactor protection system
By designing a test device that includes a controller, a relay drive circuit, and a timing circuit, the step change of the resistance signal of the reactor protection system is simulated, solving the problem that the response time of the temperature transmitter cannot be accurately measured in the existing technology, and realizing accurate response time measurement.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-26
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies cannot effectively simulate the multi-stage step changes in the resistance signal of the reactor protection system channel, resulting in the inability to accurately test the response time of the temperature transmitter.
A test device was designed, comprising a controller, a relay drive circuit, a relay circuit, and a timing circuit. The device simulates the step change in the resistance signal of a reactor protection system by controlling the change in resistance value through the opening and closing of the relay, and measures the response time using a crystal oscillator timing circuit.
It enables precise testing of the response time of the over-temperature monitoring channel of the reactor protection system, ensuring the accuracy and reliability of the test results and avoiding false triggering caused by infinite resistance.
Smart Images
Figure CN121748015A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of response time testing technology, specifically relating to an automatic testing device for the response time of an over-temperature monitoring channel in a reactor protection system. Background Technology
[0002] The reactor protection system in a nuclear power plant is a crucial system for ensuring the safe operation of the reactor. Relevant regulations impose strict requirements on the response time of the protection system's channels. Currently, the commonly used testing method involves using a signal generator and a high-speed recorder. However, this method has the following drawbacks: signal generators generally cannot simulate the multi-stage step changes in resistance signals, therefore the test does not capture the actual response time of the envelope temperature transmitter. Summary of the Invention
[0003] The purpose of this invention is to provide an automatic testing device for the response time of the over-temperature monitoring channel in a reactor protection system, thereby solving the above-mentioned technical problems.
[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0005] An automatic test device for the response time of an over-temperature monitoring channel in a reactor protection system includes a controller, a relay drive circuit, a relay circuit consisting of five relays K2 to K6, a resistor circuit consisting of six series resistors R1 to R6, and a timing circuit. The output of the resistor circuit is connected to the reactor protection system, and the output of the reactor protection system's shutdown circuit breaker is connected to the timing circuit. The controller is connected to the relay drive circuit and the timing circuit, and the relay drive circuit is connected to the relay circuit. Resistors R1 to R5 are controlled by the opening and closing of relays K2 to K5, respectively, and resistor R6 is controlled by a double-gang relay K6.
[0006] The resistor values of the resistor circuit are designed as follows: R1 = 195Ω, R2 = 1Ω, R3 = 2Ω, R4 = 4Ω, R5 = 8Ω, and R6 = 6Ω.
[0007] The function of resistors R1 to R5 is to set the initial resistance value, so as to achieve a resistance value output of 195Ω to 205Ω.
[0008] Resistor R6 is the trigger resistor, enabling a step output from a 6Ω resistor.
[0009] The two ends of relay K2 are connected to the two ends of resistor R2, the two ends of relay K3 are connected to the two ends of resistor R3, the two ends of relay K4 are connected to the two ends of resistor R4, and the two ends of relay K5 are connected to the two ends of resistor R5.
[0010] The first set of contacts of relay K6 is connected to both ends of resistor R6, and the second set of contacts and 5V voltage are connected to the timing circuit.
[0011] The timing circuit uses a crystal oscillator with a frequency of 1 MHz, and the measurement accuracy is higher than 1 µs.
[0012] When relay K6 is closed, there is no step resistance output, and the voltage monitored by the timing circuit is high. When relay K6 is opened, the resistance value collected by the reactor protection system jumps by 6Ω instantaneously, and the voltage monitored by the timing circuit becomes low, and timing begins.
[0013] The test channel is determined, and the output of the resistor circuit is connected to the reactor protection system. The output of the reactor protection system's shutdown circuit breaker is connected to the timing circuit. The initial resistance value is preset. The resistor circuit is used to simulate the resistance change of the field temperature sensor and inputs it to the temperature transmitter card of the reactor protection system. The controller controls the opening and closing of relays K2 to K5 through the relay drive circuit to realize the initial value of the input resistance of the reactor protection system and the step resistance output. The controller controls relay K6 through the relay drive circuit. When relay K6 is opened, it simulates the step change of the input resistance of the reactor protection system. At the same time, the timing circuit starts timing. The reactor protection system converts the resistance signal into an electrical signal. When the electrical signal exceeds the shutdown threshold, it drives the reactor protection system shutdown relay to act. When the timing circuit receives the reactor protection system shutdown relay flip signal, the timing stops. The time recorded at this time is the response time of the reactor protection system over-temperature monitoring channel.
[0014] The beneficial effects achieved by this invention are as follows:
[0015] In this invention, the resistance value is switched incrementally based on the original value, preventing the monitoring channel resistance from becoming infinite. In the de-energized state and immediately after power-on, all relay switches are closed, meaning the output resistance is at its minimum, ensuring that the reactor protection system's shutdown signal is not triggered. The initial resistance value can be set in multiple levels, from 195Ω to 205Ω, in 1Ω increments. The resistance circuit uses a programmable resistor array module, which employs electromagnetic relays and a real resistor network. The resistors are high-precision, low-temperature drift, non-inductive resistors with an accuracy of 0.01% and a temperature coefficient of 2PPM, enabling programmable real resistance output within a range of 195Ω-211Ω. The timing circuit uses a crystal oscillator with a frequency of 1MHz and an accuracy of 1µs. Test results are automatically displayed. Attached Figure Description
[0016] Figure 1 A schematic diagram of an automatic test device for the response time of an over-temperature monitoring channel in a reactor protection system;
[0017] Figure 2 This is a flowchart of an automatic testing method for the response time of an over-temperature monitoring channel in a reactor protection system. Detailed Implementation
[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0019] like Figure 1 As shown, an automatic test device for the response time of an over-temperature monitoring channel in a reactor protection system includes a controller 1, a relay drive circuit 2, a relay circuit 3 consisting of five relays K2 to K6, a resistor circuit 4 consisting of six high-precision resistors R1 to R6, and timing circuits 5 and 6, which are the over-temperature monitoring channels of the reactor protection system and the devices under test.
[0020] Resistor circuit 4 consists of six resistors connected in series, with the following resistance values: R1 = 195Ω, R2 = 1Ω, R3 = 2Ω, R4 = 4Ω, R5 = 8Ω, and R6 = 6Ω. R1 to R5 are used for initial resistance setting; controlled by relays K2 to K5, they can achieve output resistance values ranging from 195Ω to 205Ω. R6 is the trigger resistor, controlled by a double relay K6, enabling a step output of 6Ω. The minimum output value of R1 to R6, controlled by the relays, is 195Ω, higher than the lower limit of the temperature transmitter's range. The maximum output value of R1 to R6 is 211Ω, lower than the upper limit of the temperature transmitter's range. This design ensures the normal operation of the temperature transmitter. The resistance values of R1 to R6 can be modified according to the temperature transmitter's range.
[0021] Relay circuit 3 consists of K2 to K6, which is controlled by a relay drive circuit. K2 is connected to R2, K3 is connected to R3, K4 is connected to R4, K5 is connected to R5, and K6 is a double relay. The first pair of contacts is connected to R6, and the second pair of contacts and 5Vdc are connected to the response time timing circuit 5.
[0022] Since the timing circuit cannot monitor changes in resistance value, a 5V voltage is connected in series with one pair of contacts of the double relay K6. This allows the timing circuit to monitor changes in the step resistance. The implementation is as follows: when K6 is closed, there is no step resistance output, and the voltage monitored by the timing circuit is high. When K6 is opened, the resistance value acquired by the reactor protection system experiences a momentary 6Ω step, and the voltage monitored by the timing circuit simultaneously drops to low, initiating the timing process. The timing circuit 5 uses a 1MHz crystal oscillator, achieving a measurement accuracy higher than 1µs.
[0023] The testing process is as follows Figure 2As shown: System initialization ensures the channel is functioning correctly before the test. The test channel is determined, and the output of the resistor circuit is connected to the reactor protection system. The output of the reactor protection system's shutdown circuit breaker is connected to the timing circuit. An initial resistance value is preset; the resistor circuit simulates the resistance change of the field temperature sensor, inputting it to the temperature transmitter card of the reactor protection system. The controller controls the opening and closing of relays K2 to K5 via the relay drive circuit to simulate the initial value of the reactor protection system's input resistance. A step resistance output is then implemented; the controller controls relay K6 via the relay drive circuit. When K6 opens, it simulates a step change in the reactor protection system's input resistance, and the timing circuit starts timing simultaneously. The reactor protection system converts the resistance signal into an electrical signal. When the electrical signal exceeds the shutdown threshold, it drives the reactor protection system's shutdown relay to activate. When the timing circuit receives the reactor protection system's shutdown relay flip signal, the timing stops; the recorded time is the response time of the reactor protection system's over-temperature monitoring channel.
Claims
1. An automatic testing device for the response time of an over-temperature monitoring channel in a reactor protection system, characterized in that: It includes a controller, a relay drive circuit, a relay circuit consisting of five relays K2 to K6, a resistor circuit consisting of six series resistors R1 to R6, a timing circuit, the output of the resistor circuit is connected to the reactor protection system, the output of the reactor protection system's shutdown circuit breaker is connected to the timing circuit, the controller is connected to the relay drive circuit and the timing circuit, the relay drive circuit is connected to the relay circuit, resistors R1 to R5 are controlled by the opening and closing of relays K2 to K5 respectively, and resistor R6 is controlled by a double relay K6.
2. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The resistor values for the resistor circuit are designed as follows: R1 = 195Ω, R2 = 1Ω, R3 = 2Ω, R4 = 4Ω, R5 = 8Ω, and R6 = 6Ω.
3. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The function of resistors R1 to R5 is to set the initial resistance value, so as to achieve a resistance value output of 195Ω to 205Ω.
4. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: Resistor R6 is the trigger resistor, enabling a step output from a 6Ω resistor.
5. The automatic testing device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The two ends of relay K2 are connected to the two ends of resistor R2, the two ends of relay K3 are connected to the two ends of resistor R3, the two ends of relay K4 are connected to the two ends of resistor R4, and the two ends of relay K5 are connected to the two ends of resistor R5.
6. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The first set of contacts of relay K6 is connected to both ends of resistor R6, and the second set of contacts and 5V voltage are connected to the timing circuit.
7. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The timing circuit uses a crystal oscillator with a frequency of 1 MHz, and the measurement accuracy is higher than 1 µs.
8. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: When relay K6 is closed, there is no step resistance output, and the voltage monitored by the timing circuit is high. When relay K6 is opened, the resistance value collected by the reactor protection system jumps by 6Ω instantaneously, and the voltage monitored by the timing circuit becomes low, and timing begins.
9. The automatic test device for the response time of the over-temperature monitoring channel of the reactor protection system according to claim 1, characterized in that: The test channel is determined, and the output of the resistor circuit is connected to the reactor protection system. The output of the reactor protection system's shutdown circuit breaker is connected to the timing circuit. The initial resistance value is preset. The resistor circuit is used to simulate the resistance change of the field temperature sensor and inputs it to the temperature transmitter card of the reactor protection system. The controller controls the opening and closing of relays K2 to K5 through the relay drive circuit to realize the initial value of the input resistance of the reactor protection system and the step resistance output. The controller controls relay K6 through the relay drive circuit. When relay K6 is opened, it simulates the step change of the input resistance of the reactor protection system. At the same time, the timing circuit starts timing. The reactor protection system converts the resistance signal into an electrical signal. When the electrical signal exceeds the shutdown threshold, it drives the reactor protection system shutdown relay to act. When the timing circuit receives the reactor protection system shutdown relay flip signal, the timing stops. The time recorded at this time is the response time of the reactor protection system over-temperature monitoring channel.