CN118034403A

CN118034403A - Temperature control circuit, method and temperature control system of semiconductor refrigerator

Info

Publication number: CN118034403A
Application number: CN202410274477.2A
Authority: CN
Inventors: 胡佳文
Original assignee: Shanghai Mi Silicon Technology Co ltd
Current assignee: Shanghai Mi Silicon Technology Co ltd
Priority date: 2024-03-11
Filing date: 2024-03-11
Publication date: 2024-05-14

Abstract

The application provides a temperature control circuit, a temperature control method and a temperature control system of a semiconductor refrigerator, which relate to the technical field of semiconductor refrigeration control, wherein the temperature control circuit comprises: the linear voltage stabilizer and the control circuit comprise a PID control circuit, a parallel current threshold comparison circuit and a parallel voltage threshold comparison circuit; the linear voltage stabilizer provides a first working voltage for the semiconductor refrigerator; the control circuit provides a second working voltage for the semiconductor refrigerator; the linear voltage stabilizer is also connected with the input end of the control circuit, detects the current flowing through the semiconductor refrigerator, and inputs the detection result to the control circuit; the control circuit compares the detection result with the current limiting threshold value to obtain a threshold value comparison result, and the current control loop or the voltage control loop is conducted according to the threshold value comparison result. By adopting the temperature control circuit, the temperature control method and the temperature control system of the semiconductor refrigerator, the problem that the time required by the semiconductor refrigerator to reach the expected voltage is long is solved.

Description

Temperature control circuit, method and temperature control system of semiconductor refrigerator

Technical Field

The application relates to the technical field of semiconductor refrigeration control, in particular to a temperature control circuit, a temperature control method and a temperature control system of a semiconductor refrigerator.

Background

The laser can generate light beams with high brightness, single color and good directivity, so that the laser becomes an ideal light source in optical measurement, and is widely applied to the field of optical measurement. However, the laser is affected by the ambient temperature and the power consumption of the laser, so that the internal temperature change of the laser affects the working performance of the laser, and the laser needs to be controlled at a constant temperature. Currently, lasers are typically self-contained semiconductor refrigerators (Thermoelectric Cooler, TEC) that are used to maintain stability of the laser operating temperature. The temperature of the laser is regulated and controlled by controlling the current in the thermoelectric module based on the thermoelectric effect principle. TEC belongs to a first-order control system, and the temperature control precision is poor, so that a temperature control circuit is adopted to improve the temperature control precision of the TEC by controlling the TEC to reach the expected voltage. The existing temperature control circuit comprises a current limiting control loop and a voltage control loop, wherein the current limiting control loop is loaded on the periphery of the voltage control loop.

However, to avoid system instability caused by the interaction of the current limiting control loop and the voltage control loop, the time constant of the current limiting control loop is typically made much larger than the voltage control loop, resulting in a longer step response time, resulting in a longer time required for the TEC to reach the desired voltage.

Disclosure of Invention

In view of the above, the present application is to provide a temperature control circuit, a temperature control method and a temperature control system for a semiconductor refrigerator, which solve the problem that the time required for the semiconductor refrigerator to reach the desired voltage is long.

In a first aspect, an embodiment of the present application provides a temperature control circuit of a semiconductor refrigerator, where the temperature control circuit includes a linear voltage regulator and a control circuit, the control circuit includes a PID control circuit, a current threshold comparison circuit and a voltage threshold comparison circuit that are set in parallel, a current control loop is formed based on the current threshold comparison circuit and the PID control circuit, and a voltage control loop is formed based on the voltage threshold comparison circuit and the PID control circuit;

The output end of the linear voltage stabilizer is connected with one end of the semiconductor refrigerator, and provides a first working voltage for the semiconductor refrigerator;

The output end of the control circuit is connected with the other end of the semiconductor refrigerator to provide a second working voltage for the semiconductor refrigerator;

the linear voltage stabilizer is also connected with the input end of the control circuit, detects the current flowing through the semiconductor refrigerator, and inputs the detection result to the control circuit;

The control circuit compares the detection result with the current limiting threshold value to obtain a threshold value comparison result, and the current control loop or the voltage control loop is conducted according to the threshold value comparison result so as to adjust the current or the voltage of the semiconductor refrigerator.

Optionally, the temperature control circuit further comprises a current-voltage converter and a voltage comparison circuit; the input end of the voltage comparison circuit is connected with the semiconductor refrigerator, and the voltage at two ends of the semiconductor refrigerator is obtained to determine the voltage difference of the refrigerator; the input end of the current-voltage converter is connected with the output end of the linear voltage stabilizer, the current detected by the linear voltage stabilizer is converted into voltage, the output end of the current-voltage converter is connected with the first input end of the control circuit, and the converted voltage is input to the control circuit; the second input end of the control circuit is connected with the output end of the voltage comparison circuit to obtain the voltage difference of the refrigerator; when the target control loop is a current control loop, the control circuit determines a second working voltage according to the converted voltage and the current limiting threshold value, and when the target control loop is a voltage control loop, the control circuit determines the second working voltage according to the voltage difference of the refrigerator and the set voltage.

Optionally, the PID control circuit comprises an integrator, a PID subtractor, a differentiator and a dc power converter; the input end of the integrator is used as a first input end of the PID control circuit, is connected with the output end of the current threshold comparison circuit through a first switch, is connected with the output end of the voltage threshold comparison circuit through a second switch, and integrates the current limiting value output by the current threshold comparison circuit or the voltage limiting value output by the voltage threshold comparison circuit; the output end of the PID subtracter is connected with the DC power converter, so that the PID control circuit regulates the current or voltage of the semiconductor refrigerator according to the integration result of the integrator, the differentiation result of the differentiator and the proportional amplification result corresponding to the proportional link coefficient.

Optionally, the control circuit further comprises a loop control circuit; the output end of the current threshold comparison circuit is connected with the input end of the loop control circuit, and the threshold comparison result is input into the loop control circuit; the output end of the loop control circuit is respectively connected with the first switch and the second switch, and the opening and closing of the first switch or the second switch are controlled according to the threshold comparison result so as to select to conduct the current control loop or the voltage control loop.

Optionally, the current limiting threshold includes a refrigeration mode current limiting threshold and a heating mode current limiting threshold, and the current threshold comparison circuit includes a refrigeration mode control circuit and a heating mode control circuit; the input end of the refrigeration mode control circuit is used as the input end of the current threshold value comparison circuit to be connected with the output end of the current-voltage converter, and whether the detection result is larger than the refrigeration mode current-limiting threshold value or not is determined to obtain a first threshold value comparison result; the input end of the heating mode control circuit is connected with the input end of the refrigerating mode control circuit, and whether the detection result is smaller than the heating mode current limiting threshold value or not is determined to obtain a second threshold value comparison result; the output end of the refrigeration mode control circuit and the output end of the heating mode control circuit are used as the output ends of the current threshold comparison circuit to be connected with the loop control circuit, so that the loop control circuit controls the first switch and the second switch according to the first threshold comparison result and the second threshold comparison result.

Optionally, the refrigeration mode control circuit includes a refrigeration mode subtractor, a refrigeration mode comparator, and a third switch; the input end of the refrigeration mode subtracter is used as the input end of the refrigeration mode control circuit to be connected with the output end of the current-voltage converter, and the difference value between the converted voltage and the refrigeration mode current-limiting threshold value is calculated to obtain a refrigeration pressure difference value; the output end of the refrigeration mode subtracter is connected with the input end of the refrigeration mode comparator, and the refrigeration pressure difference value is input into the refrigeration mode comparator, so that the refrigeration mode comparator determines a first threshold comparison result according to the refrigeration pressure difference value; the output end of the refrigeration mode comparator is connected with the third switch, and the conduction of the third switch is controlled by using the comparison result of the first threshold value; the output end of the refrigeration mode subtracter is also connected with a third switch, so that when the current control loop is started and the third switch is conducted, the refrigeration pressure difference value is sent to the PID control circuit.

Optionally, the heating mode control circuit includes a heating mode subtractor, a heating mode comparator, and a fourth switch; the input end of the heating mode subtracter is used as the input end of the heating mode control circuit to be connected with the input end of the refrigerating mode control circuit, and the difference value between the converted voltage and the heating mode current limiting threshold value is calculated to obtain a heating pressure difference value; the output end of the heating mode subtracter is connected with the input end of the heating mode comparator, and the heating pressure difference value is input into the heating mode comparator, so that the heating mode comparator determines a second threshold comparison result according to the heating pressure difference value; the output end of the heating mode comparator is connected with the fourth switch, and the second threshold comparison result is utilized to control the conduction of the fourth switch; the output end of the heating mode subtracter is also connected with a fourth switch so as to send the heating pressure difference value to the PID control circuit when the current control loop is opened and the fourth switch is turned on.

Optionally, the loop control circuit includes an or circuit and an inverter; the OR gate circuit is used as the input end of the loop control circuit and is connected with the output end of the current threshold comparison circuit, receives the threshold comparison result output by the current threshold comparison circuit, and determines the conduction control signal of the first switch according to the threshold comparison result; the output end of the OR gate circuit is also connected with the input end of the inverter, the conduction control signal of the first switch is sent to the inverter, and the inverter inverts the conduction control signal of the first switch to obtain the conduction control signal of the second switch.

In a second aspect, an embodiment of the present application further provides a temperature control method of a semiconductor refrigerator, where the method includes:

providing a first operating voltage and a second operating voltage for the semiconductor refrigerator;

Detecting the current flowing through the semiconductor refrigerator, and comparing the detection result with a current limiting threshold value to obtain a threshold value comparison result;

and conducting a current control loop or a voltage control loop according to the threshold comparison result so as to regulate the current or the voltage of the semiconductor refrigerator.

In a third aspect, an embodiment of the present application further provides a temperature control system, where the temperature control system includes a semiconductor refrigerator and a temperature control circuit of the semiconductor refrigerator.

The embodiment of the application has the following beneficial effects:

The temperature control circuit, the temperature control method and the temperature control system of the semiconductor refrigerator can provide two parallel control loops for the semiconductor refrigerator according to the threshold comparison result to adjust the working voltage of the semiconductor refrigerator through the target control loop, and the two control loops are parallel and cannot influence each other, so that the stability of the system is improved, the time constant of the control loop is reduced, and compared with the temperature control circuit method of the semiconductor refrigerator in the prior art, the problem that the time required for the semiconductor refrigerator to reach the expected voltage is longer is solved.

In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows a circuit diagram of a temperature control circuit of a semiconductor refrigerator according to an embodiment of the present application;

Fig. 2 shows a flowchart of a temperature control method of a semiconductor refrigerator according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. Based on the embodiments of the present application, every other embodiment obtained by a person skilled in the art without making any inventive effort falls within the scope of protection of the present application.

It is noted that, before the present application is proposed, the laser can generate a light beam with high brightness, single color and good directivity, so that the light beam becomes an ideal light source in optical measurement, and the laser is widely applied in the field of optical measurement. However, the laser is affected by the ambient temperature and the power consumption of the laser, so that the internal temperature change of the laser affects the working performance of the laser, and the laser needs to be controlled at a constant temperature. Currently, lasers are typically self-contained semiconductor refrigerators (Thermoelectric Cooler, TEC) that are used to maintain stability of the laser operating temperature. The temperature of the laser is regulated and controlled by controlling the current in the thermoelectric module based on the thermoelectric effect principle. TEC belongs to a first-order control system, and the temperature control precision is poor, so that a temperature control circuit is adopted to improve the temperature control precision of the TEC by controlling the TEC to reach the expected voltage. In the prior art, a current-limiting control loop is generally loaded on the periphery of a voltage control loop, so as to avoid system instability caused by interaction of the current-limiting control loop and the voltage control loop, namely, avoid interaction between the current-limiting control loop and the voltage control loop, the time constant of the current-limiting control loop needs to be made to be much larger than that of the voltage control loop, and thus, the step response time is longer, but because the current-limiting control loop and the voltage control loop act simultaneously, the time constant of the whole temperature control circuit is determined by the time constant of the current-limiting control loop, and then, the time constant of the whole temperature control circuit is longer, and the time required for TEC to reach the expected voltage is longer.

Based on the above, the embodiment of the application provides a temperature control circuit of a semiconductor refrigerator, so as to shorten the time required for the TEC to reach the expected voltage.

Referring to fig. 1, fig. 1 is a circuit diagram of a temperature control circuit of a semiconductor refrigerator according to an embodiment of the application. As shown in fig. 1, a temperature control circuit of a semiconductor refrigerator according to an embodiment of the present application includes a linear voltage stabilizer 100 and a control circuit 200.

The control circuit comprises a PID control circuit, a current threshold comparison circuit and a voltage threshold comparison circuit which are arranged in parallel, wherein a current control loop is formed based on the current threshold comparison circuit and the PID control circuit, and a voltage control loop is formed based on the voltage threshold comparison circuit and the PID control circuit.

The output terminal of the linear voltage stabilizer 100 is connected to one terminal of the semiconductor refrigerator 300, and provides the first operating voltage to the semiconductor refrigerator 300.

An output terminal of the control circuit 200 is connected to the other end of the semiconductor refrigerator 300, and provides a second operating voltage to the semiconductor refrigerator 300.

The linear regulator 100 is also connected to an input terminal of the control circuit 200, detects a current flowing through the semiconductor refrigerator 300, and inputs the detection result to the control circuit 200.

The control circuit 200 compares the detection result with the current limiting threshold value to obtain a threshold value comparison result, and turns on the current control loop or the voltage control loop according to the threshold value comparison result to regulate the current or the voltage of the semiconductor refrigerator.

Here, the linear voltage regulator 100 may refer to an LDO voltage regulator, where the linear voltage regulator 100 is a dc-ac voltage regulator with an input voltage greater than an output voltage, an input terminal of the linear voltage regulator 100 is connected to the input voltage, an input terminal of a negative electrode of the linear voltage regulator 100 is connected to an output terminal of the linear voltage regulator 100, and the linear voltage regulator 100 is configured to step down the input voltage to obtain a first working voltage provided for the semiconductor refrigerator 300, where the first working voltage is a voltage at an upper end of the TEC. The output end of the control circuit 200 is connected with the lower end of the semiconductor refrigerator 300 to provide the semiconductor refrigerator 300 with a second working voltage, and the difference between the first working voltage and the second working voltage is the refrigerator voltage difference。

The current control loop and the voltage control loop are two parallel control loops, and the temperature control circuit further comprises a current-voltage converter 400 and a voltage comparison circuit 500; the input end of the voltage comparison circuit 500 is connected with the semiconductor refrigerator 300 to obtain the voltages of the two ends of the semiconductor refrigerator 300 so as to determine the refrigerator voltage difference; The input end of the current-voltage converter 400 is connected with the output end of the linear voltage stabilizer 100, a current sensor in the linear voltage stabilizer 100 detects the current flowing through the TEC, the detection result is sent to the current-voltage converter 400, the current-voltage converter 400 converts the detected current into voltage, the output end of the current-voltage converter 400 is connected with the first input end of the control circuit 200, and the converted voltage is input to the control circuit 200; a second input end of the control circuit 200 is connected with an output end of the voltage comparison circuit 500 to obtain a refrigerator voltage difference/>。

Here, the purpose of the current control loop is to control the current value of the TEC to be a set current threshold value, and the purpose of the voltage control loop is to control the voltage value of the TEC to be a set voltage threshold value, and any control method can control the temperature by controlling the power of the TEC.

The control circuit 200 compares the voltage input from the current-to-voltage converter 400 with a current limit threshold value, and determines whether to turn on the current control loop or the voltage control loop according to the threshold value comparison result. When the target control loop is a current control loop, the control circuit 200 determines a second working voltage according to the converted voltage and the current limiting threshold value, and when the target control loop is a voltage control loop, the control circuit 200 determines a second working voltage according to the voltage difference of the refrigeratorThe set voltage determines a second operating voltage.

Here, the current-voltage converter 400 is an I/V current-voltage converter for converting a current into a voltage. The voltage comparison circuit 500 includes a subtractor SUB0, one end of the subtractor SUB0 is connected with the upper end of the TEC to obtain a first working voltage, and the other end of the subtractor is connected with the lower end of the TEC to obtain a second working voltage. Calculating the difference between the first working voltage and the second working voltage by a subtracter to obtain the voltage difference of the refrigeratorThe voltage comparison circuit 500 compares the refrigerator voltage difference/>The control circuit 200 is input via a second input of the control circuit 200.

If the control circuit 200 is turned on, that is, the current control circuit performs current mode control on the TEC, the current value of the TEC is controlled to be the set current threshold value in the current control mode. If the voltage control loop is turned on in the control circuit 200, that is, the voltage mode control is performed on the TEC, the voltage value of the TEC is controlled to be the set voltage threshold value in the voltage control mode.

The control circuit 200 includes a current threshold comparison circuit 210, a voltage threshold comparison circuit 220, and a PID control circuit 230; an input end of the current threshold comparison circuit 210 is used as a first input end of the control circuit 200 to be connected with an output end of the current-voltage converter 400, converted voltage is obtained from the current-voltage converter 400, an output end of the current threshold comparison circuit 210 is connected with a first input end of the PID control circuit 230 through a first switch K1, and an output end of the PID control circuit 230 is connected with the other end of the semiconductor refrigerator to form a current control loop; an input terminal of the voltage threshold comparison circuit 220 is connected as a second input terminal of the control circuit 200 to an output terminal of the voltage comparison circuit 500 to obtain a refrigerator voltage differenceThe output end of the voltage threshold comparison circuit 220 is connected with the first input end of the PID control circuit 230 through the second switch K2, and the output end of the PID control circuit 230 is connected with the other end of the semiconductor refrigerator to form a voltage control loop; the output of the voltage comparison circuit 500 is also connected to a second input of the PID control circuit 230.

The control circuit 200 also includes a loop control circuit 213; an output terminal of the current threshold value comparison circuit 210 is connected to an input terminal of the loop control circuit 213, and a threshold value comparison result is input to the loop control circuit 213; the output end of the loop control circuit 213 is connected to the first switch K1 and the second switch K2, and controls the first switch K1 or the second switch K2 to be turned on or off according to the threshold comparison result, so as to select the on current control loop or the voltage control loop.

The current limiting threshold includes a cooling mode current limiting threshold and a heating mode current limiting threshold, and the current threshold comparison circuit 210 includes a cooling mode control circuit 211 and a heating mode control circuit 212; an input end of the refrigeration mode control circuit 211 is used as an input end of the current threshold value comparison circuit 210 to be connected with an output end of the current-voltage converter 400, and whether the detection result is larger than a refrigeration mode current limiting threshold value is determined, so that a first threshold value comparison result is obtained; an input end of the heating mode control circuit 212 is connected with an input end of the refrigerating mode control circuit 211, whether the detection result is smaller than a heating mode current limiting threshold value is determined, and a second threshold value comparison result is obtained; the output terminal of the cooling mode control circuit 211 and the output terminal of the heating mode control circuit 212 are connected to the loop control circuit 213 as the output terminal of the current threshold comparison circuit 210, so that the loop control circuit 213 controls the first switch K1 and the second switch K2 according to the first threshold comparison result and the second threshold comparison result.

The cooling mode control circuit 211 includes a cooling mode subtractor SUB1, a cooling mode comparator CMP1, and a third switch K3; the input end of the refrigeration mode subtracter SUB1 is used as the input end of the refrigeration mode control circuit 211 to be connected with the output end of the current-voltage converter 400, and the difference value between the converted voltage and the refrigeration mode current limiting threshold value is calculated to obtain a refrigeration pressure difference value; the output end of the refrigeration mode subtracter SUB1 is connected with the input end of the refrigeration mode comparator CMP1, and the refrigeration pressure difference value is input into the refrigeration mode comparator CMP1, so that the refrigeration mode comparator CMP1 determines a first threshold comparison result according to the refrigeration pressure difference value; the output end of the refrigeration mode comparator CMP1 is connected with the third switch K3, and the conduction of the third switch K3 is controlled by using the comparison result of the first threshold value; the output end of the subtractor SUB1 is further connected to the third switch K3, so as to send the differential refrigeration pressure value to the PID control circuit 230 when the current control loop is turned on and the third switch K3 is turned on.

Specifically, in the cooling mode, the output voltage (first operating voltage) of the linear regulator 100 is higher than the output voltage (second operating voltage) of the control circuit 200, and the current flows from the linear regulator 100 through the TEC and then flows into the control circuit 200. When the output voltage of the current-to-voltage converter 400 is greater than the refrigeration mode current limit threshold, the refrigeration mode comparator output logic value 1 turns on the third switch, so that the difference between the TEC current and the refrigeration mode current limit threshold is connected to the current limit link coefficient amplifier.

The heating mode control circuit 212 includes a heating mode subtractor SUB2, a heating mode comparator CMP2, and a fourth switch K4; the input end of the heating mode subtracter SUB2 is used as the input end of the heating mode control circuit 212 to be connected with the input end of the refrigerating mode control circuit 211, and the difference between the converted voltage and the heating mode current limiting threshold value is calculated to obtain a heating pressure difference value; the output end of the heating mode subtracter SUB2 is connected with the input end of the heating mode comparator CMP2, and the heating pressure difference value is input into the heating mode comparator CMP2, so that the heating mode comparator CMP2 determines a second threshold value comparison result according to the heating pressure difference value; the output end of the heating mode comparator CMP2 is connected with the fourth switch K4, and the second threshold comparison result is utilized to control the conduction of the fourth switch K4; the output end of the heating mode subtractor SUB2 is further connected to the fourth switch K4, so as to send the heating voltage difference to the PID control circuit 230 when the current control loop is turned on and the fourth switch K4 is turned on.

In the heating mode, the output voltage (second operating voltage) of the control circuit 200 is higher than the output voltage (first operating voltage) of the linear regulator 100, and current flows from the control circuit 200 through the TEC into the linear regulator 100. When the output voltage of the current-to-voltage converter 400 is smaller than the heating mode current-limiting threshold, the heating mode comparator outputs a logic value 1 to turn on the fourth switch, so that the difference between the TEC current and the heating mode current-limiting threshold is connected to the current-limiting link coefficient amplifier.

The refrigerating mode current limiting threshold value and the heating mode current limiting threshold value are both values for voltage comparison. Illustratively, the cooling mode current limit threshold is positive and the heating mode current limit threshold is negative.

The current limiting threshold value of the refrigeration mode is 10V, and the current limiting threshold value of the heating mode isV is an example, when the converted voltage output from the current-to-voltage converter 400 is 12V, SUB1 calculates/>2V is the cold-pressing difference value, 2V is input into the CMP1, the CMP1 compares the 2V with the first set value 0, the first threshold comparison result is 1, the conduction of K3 is controlled, and meanwhile, when K1 is also conducted, the cold-pressing difference value 2V and the current-limiting link coefficient/>The multiplication results in a current limit value, which is input to the PID control circuit 230 to cause the PID control circuit to adjust the second operating voltage according to the current limit value. Similarly, SUB2 calculation/>27V is the difference of the hot pressing, and 27V and/>Multiplication to obtainInput into CMP2, CMP2 will/>And comparing 27V with a second set value of 0, and controlling K4 to be disconnected if the second threshold comparison result is 0. At this time, the TEC is subjected to cooling mode control.

When the converted voltage output by the current-voltage converter 400 is20V, SUB1 calculation，/>30V is the cold pressing difference value, and will/>30V input into CMP1, CMP1 will/>And comparing 30V with a first set value of 0, and controlling K3 to be disconnected if the first threshold comparison result is 0. Similarly, SUB2 calculation，/>5V is the difference of the hot pressing and the temperature will be/>5V and/>And 5V is obtained after multiplication, 5V is input into the CMP2, the CMP2 compares the 5V with a second set value 0, and if the second threshold comparison result is determined to be 1, the conduction of the K4 is controlled. At this time, the TEC is controlled in a heating mode. Meanwhile, when K1 is also conducted, the heating pressure difference value/>5V and Current limiting Link coefficient/>The multiplication results in a current limit value, which is input to the PID control circuit 230 to cause the PID control circuit to adjust the second operating voltage according to the current limit value. Wherein the current limiting link coefficient/>Playing a role in numerical value amplification.

Conversely, when the converted voltage output from the current-to-voltage converter 400 is 5V, SUB1 calculates，/>5V is the cold pressing difference value, and will/>5V input into CMP1, CMP1 will/>And comparing the 5V with a first set value of 0, and controlling K3 to be disconnected if the first threshold comparison result is 0. Similarly, SUB2 calculation20V is the difference of the hot pressing, 20V and/>Multiplication to obtainInput into CMP2, CMP2 will/>And comparing 20V with a second set value of 0, and controlling K4 to be disconnected if the second threshold comparison result is 0. At this time, both K3 and K4 are turned off, i.e. the current control loop is turned off and the voltage control loop is turned on.

It can be seen that when the converted voltage output by the current-to-voltage converter 400 is greater than the cooling mode current limit threshold or less than the heating mode current limit threshold, the current control loop is turned on, whereas when the converted voltage output by the current-to-voltage converter 400 is less than or equal to the cooling mode current limit threshold and greater than or equal to the heating mode current limit threshold, the voltage control loop is turned on. It should be noted that, when the converted voltage is equal to the current limiting threshold of the cooling mode, the first threshold comparison result is 0, and when the converted voltage is equal to the current limiting threshold of the heating mode, the second threshold comparison result is 0.

The loop control circuit 213 includes an or circuit 2131 and an inverter 2132; the or circuit 2131 is connected as an input terminal of the loop control circuit 213 to an output terminal of the current threshold comparison circuit 210, receives a threshold comparison result output by the current threshold comparison circuit 210, and determines a turn-on control signal of the first switch K1 according to the threshold comparison result; the output terminal of the or circuit 2131 is further connected to the input terminal of the inverter 2132, and sends the conduction control signal of the first switch K1 to the inverter 2132, and the inverter 2132 inverts the conduction control signal of the first switch K1 to obtain the conduction control signal of the second switch K2.

Specifically, the threshold comparison result includes a first threshold comparison result and a second threshold comparison result, and when the converted voltage output by the current-to-voltage converter 400 is greater than the cooling mode current limit threshold or less than the heating mode current limit threshold, the values of the two input ends of the or circuit 2131 are different, one is 1, and the other is 0. At this time, the output of the or circuit 2131 is 1, that is, the on control signal of the first switch K1 is 1, and K1 is turned on. At this time, when the or circuit 2131 inputs 1 to the inverter 2132 and the output of the inverter 2132 is 0, the K2 is turned off, and the entire control circuit 200 operates in the current control loop to control the current value of the TEC to be the set current threshold value.

When the converted voltage output from the current-to-voltage converter 400 is less than or equal to the cooling mode current limit threshold and greater than or equal to the heating mode current limit threshold, the values of the two input terminals of the or circuit 2131 are the same and are both 0. At this time, the output of the or circuit 2131 is 0, that is, the on control signal of the first switch K1 is 0, and K1 is turned off. After the or circuit 2131 inputs 0 to the inverter 2132, if the output of the inverter 2132 is 1, K2 is turned on, and the entire control circuit 200 operates in the voltage control loop to control the voltage value of the TEC to be the set voltage threshold value.

The voltage threshold comparison circuit 220 includes a voltage loop subtractor SUB3 and a second switch K2, the input end of the voltage loop subtractor SUB3 is connected to the output end of the voltage comparison circuit 500 as the input end of the voltage threshold comparison circuit 220, and the voltage loop subtractor SUB3 receivesCalculation/>The voltage threshold comparison circuit 220 calculates the difference from the set voltage and the integral link coefficient/>The product of (2) and the voltage limiting value is input to the PID control circuit 230 through K2, so that the PID control circuit adjusts the second operating voltage according to the voltage limiting value. Wherein the integral link coefficient/>Playing a role in numerical value amplification.

The PID control circuit 230 includes an integrator I1, a PID subtractor SUB4, a differentiator D1, and a dc power converter 231.

The input end of the integrator I1 is used as a first input end of the PID control circuit 230, connected to the output end of the current threshold value comparison circuit through the first switch K1, and connected to the output end of the voltage threshold value comparison circuit through the second switch K2, and integrates the current limit value output by the current threshold value comparison circuit or the voltage limit value output by the voltage threshold value comparison circuit. The output end of the integrator I1 is connected with the first input end of the PID subtracter SUB4, and the second input end of the PID subtracter SUB4 passes through the proportional link coefficientThe third input end of the PID subtracter SUB4 is connected with the output end of the voltage comparison circuit and passes through the differential link coefficient/>And the differentiator D1 is connected with the output end of the voltage comparison circuit, and the output end of the PID subtracter SUB4 is connected with the DC power converter 231, so that the PID control circuit 230 can control the DC power converter according to the integral result of the integrator I1, the differentiation result of the differentiator D1 and the proportional link coefficient/>The corresponding scaling results regulate the current or voltage of the semiconductor refrigerator.

The PID control circuit 230 further includes a triangular wave generator T1, the DC power converter 231 is a DC/DC power converter, and the DC power converter 231 includes a comparator CMP3, an anti-superposition circuit N1, a driver Dr2, a power switch K5, a power switch K6, an inductor L1, and a capacitor C1.

Specifically, the integrator I1, the differentiator D1 and the proportional link coefficientDifferential Link coefficient/>The combination generates an analog control signal, the analog control signal is subtracted from a triangular wave signal output by a triangular wave generator T1 in a PID subtracter SUB4, the subtraction result is compared with a numerical value in a comparator CMP3 to obtain a PWM pulse signal, and the PWM pulse signal controls power switches K5 and K6 after passing through an anti-superposition circuit N1, a driver Dr1 and a driver Dr2, wherein the anti-superposition circuit N1 has the function of avoiding the simultaneous conduction of the two power switches. When the PWM pulse signal is 1, the power switch K5 is turned on, the power switch K6 is turned off, and when the PWM pulse signal is 0, the power switch K6 is turned on, and the power switch K5 is turned off.

The integrator I1 is configured to make the static value of the controlled variable equal to a set target threshold, and when the target control loop is a current control loop, the controlled variable is a current, the set target threshold is a set current threshold, and when the target control loop is a voltage control loop, the controlled variable is a voltage, and the set target threshold is a set voltage threshold. The time constant of the whole temperature control circuit can be adjusted by adjusting the current limiting link coefficient and the integral link coefficient, the larger the two amplification coefficients are, the shorter the time constant is, and the two control loops are parallel and independent and cannot influence each other, so that the stability of the system is improved without increasing the time constant of the current control loop, and the problem of larger time constant is avoided. Meanwhile, the current limiting link coefficient of the current control loop and the integral link coefficient of the voltage control loop are mutually independent, so that the time constant of the whole temperature control circuit can be reduced only by increasing any one link coefficient, and the flexibility of system control is improved.

Here, the proportional-derivative control circuit may be regarded as an inner loop, and the current control loop and the voltage control loop may be regarded as an outer loop, and an integrator may be fitted to the inner loop. The inner and outer loops are not mutually exclusive but act simultaneously. The proportional-differential control circuit is used for compensating the phase shift of the LC outside the DC/DC power converter, so that the inner loop has enough phase margin, and the inner loop is ensured to be nested in the outer loop and also has enough phase margin, thereby avoiding oscillation. The inner loop itself is a control system, but is not sufficiently accurate to control the output voltage, and therefore an integrator is required to form an outer loop with the integrator to achieve accurate control of the output voltage.

Compared with the temperature control circuit method of the semiconductor refrigerator in the prior art, the temperature control circuit method of the semiconductor refrigerator can provide two parallel control loops for the semiconductor refrigerator according to the threshold comparison result to adjust the working voltage of the semiconductor refrigerator through the target control loop, and the two control loops are parallel and cannot influence each other, so that the time constant of the control loop is reduced while the system stability is improved, and the problem that the time required by the semiconductor refrigerator to reach the expected voltage is long is solved.

Based on the same inventive concept, the embodiment of the application also provides a temperature control method of the semiconductor refrigerator corresponding to the temperature control circuit of the semiconductor refrigerator, and because the principle of solving the problem by the method in the embodiment of the application is similar to that of the temperature control circuit of the semiconductor refrigerator in the embodiment of the application, the implementation of the method can refer to the implementation of the circuit, and the repetition is omitted.

Referring to fig. 2, fig. 2 is a flowchart of a temperature control method of a semiconductor refrigerator according to an embodiment of the application. As shown in fig. 2, the temperature control method of the semiconductor refrigerator includes:

step S601, providing a first working voltage and a second working voltage for a semiconductor refrigerator;

step S602, detecting the current flowing through the semiconductor refrigerator, and comparing the detection result with a current limiting threshold value to obtain a threshold value comparison result;

Step S603, turning on the current control loop or the voltage control loop according to the threshold comparison result to adjust the current or the voltage of the semiconductor refrigerator.

The embodiment of the application also provides a temperature control system comprising the semiconductor refrigerator and the temperature control circuit of the semiconductor refrigerator, and the specific implementation manner can be referred to the embodiment of the temperature control circuit and is not repeated here.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

Finally, it should be noted that: the above examples are only specific embodiments of the present application, and are not intended to limit the scope of the present application, but it should be understood by those skilled in the art that the present application is not limited thereto, and that the present application is described in detail with reference to the foregoing examples: any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or perform equivalent substitution of some of the technical features, while remaining within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. The temperature control circuit of the semiconductor refrigerator is characterized by comprising a linear voltage stabilizer and a control circuit, wherein the control circuit comprises a PID control circuit, a current threshold comparison circuit and a voltage threshold comparison circuit which are arranged in parallel, a current control loop is formed based on the current threshold comparison circuit and the PID control circuit, and a voltage control loop is formed based on the voltage threshold comparison circuit and the PID control circuit;

the output end of the linear voltage stabilizer is connected with one end of the semiconductor refrigerator, and a first working voltage is provided for the semiconductor refrigerator;

The output end of the control circuit is connected with the other end of the semiconductor refrigerator, and provides a second working voltage for the semiconductor refrigerator;

and the control circuit compares the detection result with a current limiting threshold value to obtain a threshold value comparison result, and conducts a current control loop or a voltage control loop according to the threshold value comparison result so as to regulate the current or the voltage of the semiconductor refrigerator.

2. The temperature control circuit of claim 1, wherein the temperature control circuit further comprises a current-to-voltage converter and a voltage comparison circuit;

The input end of the voltage comparison circuit is connected with the semiconductor refrigerator, and the voltage at two ends of the semiconductor refrigerator is obtained to determine the voltage difference of the refrigerator;

the input end of the current-voltage converter is connected with the output end of the linear voltage stabilizer, the current detected by the linear voltage stabilizer is converted into voltage, the output end of the current-voltage converter is connected with the first input end of the control circuit, and the converted voltage is input to the control circuit;

the second input end of the control circuit is connected with the output end of the voltage comparison circuit to obtain the voltage difference of the refrigerator;

when the target control loop is a current control loop, the control circuit determines a second working voltage according to the converted voltage and the current limiting threshold value, and when the target control loop is a voltage control loop, the control circuit determines the second working voltage according to the voltage difference of the refrigerator and the set voltage.

3. The temperature control circuit of claim 2, wherein the PID control circuit comprises an integrator, a PID subtractor, a differentiator, and a dc power converter;

The input end of the integrator is used as a first input end of the PID control circuit, is connected with the output end of the current threshold comparison circuit through a first switch, is connected with the output end of the voltage threshold comparison circuit through a second switch, and integrates a current limiting value output by the current threshold comparison circuit or a voltage limiting value output by the voltage threshold comparison circuit;

The output end of the PID subtracter is connected with the first input end of the PID subtracter, the second input end of the PID subtracter is connected with the output end of the voltage comparison circuit through a proportional link coefficient, the third input end of the PID subtracter is connected with the output end of the voltage comparison circuit through a differential link coefficient and the differentiator, and the output end of the PID subtracter is connected with the direct current power converter so that the PID control circuit regulates the current or the voltage of the semiconductor refrigerator according to the integral result of the integrator, the differential result of the differentiator and the proportional amplification result corresponding to the proportional link coefficient.

4. A temperature control circuit according to claim 3, wherein the control circuit further comprises a loop control circuit;

The output end of the current threshold comparison circuit is connected with the input end of the loop control circuit, and the threshold comparison result is input to the loop control circuit;

the output end of the loop control circuit is respectively connected with the first switch and the second switch, and the opening and closing of the first switch or the second switch are controlled according to a threshold comparison result so as to select a conduction current control loop or a voltage control loop.

5. The temperature control circuit of claim 4, wherein the current limit threshold comprises a cooling mode current limit threshold and a heating mode current limit threshold, and the current threshold comparison circuit comprises a cooling mode control circuit and a heating mode control circuit;

the input end of the refrigeration mode control circuit is used as the input end of the current threshold comparison circuit to be connected with the output end of the current-voltage converter, and whether the detection result is larger than the refrigeration mode current limiting threshold value or not is determined to obtain a first threshold value comparison result;

the input end of the heating mode control circuit is connected with the input end of the refrigerating mode control circuit, and whether the detection result is smaller than the heating mode current limiting threshold value or not is determined to obtain a second threshold value comparison result;

The output end of the refrigeration mode control circuit and the output end of the heating mode control circuit are used as the output ends of the current threshold comparison circuit to be connected with the loop control circuit, so that the loop control circuit controls the first switch and the second switch according to the first threshold comparison result and the second threshold comparison result.

6. The temperature control circuit of claim 5, wherein the cooling mode control circuit comprises a cooling mode subtractor, a cooling mode comparator, and a third switch;

the input end of the refrigeration mode subtracter is used as the input end of the refrigeration mode control circuit to be connected with the output end of the current-voltage converter, and the difference value between the converted voltage and the refrigeration mode current-limiting threshold value is calculated to obtain a refrigeration pressure difference value;

The output end of the refrigeration mode subtracter is connected with the input end of the refrigeration mode comparator, and the refrigeration pressure difference value is input into the refrigeration mode comparator, so that the refrigeration mode comparator determines a first threshold comparison result according to the refrigeration pressure difference value;

the output end of the refrigeration mode comparator is connected with the third switch, and the conduction of the third switch is controlled by using the first threshold comparison result;

The output end of the refrigeration mode subtracter is also connected with the third switch, so that the refrigeration pressure difference value is sent to the PID control circuit when the current control loop is started and the third switch is conducted.

7. The temperature control circuit of claim 5, wherein the heating mode control circuit comprises a heating mode subtractor, a heating mode comparator, and a fourth switch;

The input end of the heating mode subtracter is used as the input end of the heating mode control circuit and is connected with the input end of the refrigerating mode control circuit, and the difference value between the converted voltage and the heating mode current limiting threshold value is calculated to obtain a heating pressure difference value;

the output end of the heating mode subtracter is connected with the input end of the heating mode comparator, and the heating pressure difference value is input into the heating mode comparator, so that the heating mode comparator determines a second threshold comparison result according to the heating pressure difference value;

the output end of the heating mode comparator is connected with the fourth switch, and the conduction of the fourth switch is controlled by using the second threshold comparison result;

The output end of the heating mode subtracter is also connected with the fourth switch, so that the heating pressure difference value is sent to the PID control circuit when the current control loop is started and the fourth switch is turned on.

8. The temperature control circuit of claim 4, wherein the loop control circuit comprises an or gate and an inverter;

The OR gate circuit is used as the input end of the loop control circuit and is connected with the output end of the current threshold comparison circuit, receives the threshold comparison result output by the current threshold comparison circuit, and determines the conduction control signal of the first switch according to the threshold comparison result;

The output end of the OR gate circuit is also connected with the input end of the inverter, the conduction control signal of the first switch is sent to the inverter, and the inverter inverts the conduction control signal of the first switch to obtain the conduction control signal of the second switch.

9. A method of controlling the temperature of a semiconductor refrigerator, comprising:

10. A temperature control system, characterized in that the temperature control system comprises a semiconductor refrigerator and a temperature control circuit of the semiconductor refrigerator according to any one of claims 1 to 8.