CN114234473B - Electromechanical control system and method for all-solid-state energy conversion refrigerating device - Google Patents

Abstract

The invention discloses an electromechanical control system of an all-solid-state energy conversion refrigerating device, which comprises a synchronous control upper computer, a current direction control unit, a motor drive control unit and a direct-current power supply, wherein the synchronous upper computer is respectively connected with the current direction control unit and the motor drive control unit; the current direction control unit is connected with a thermoelectric magnetic refrigeration element of the all-solid-state energy conversion refrigeration device and applies current to the thermoelectric magnetic refrigeration element; the motor driving control unit is connected with a stepping motor of the all-solid-state energy conversion refrigerating device and drives the stepping motor to rotate. The invention also provides a control method. The invention has the beneficial effects that: the synchronous control upper computer sends different control instructions to the current direction control unit and the motor driving control unit respectively, so that the thermal electromagnetic refrigeration element can reach a required working area according to a set time period under the driving of the stepping motor, and the required working current direction and magnitude are applied to the thermal electromagnetic refrigeration element.

Description

Electromechanical control system and method for all-solid-state energy conversion refrigerating device

Technical Field

The invention relates to an electromechanical control method, in particular to an electromechanical control system and method of an all-solid-state energy conversion refrigerating device based on thermal electromagnetic coupling.

Background

Aiming at the problem that the efficiency of the existing single magnetic refrigeration or single thermoelectric refrigeration is difficult to reach the traditional steam compression refrigeration level, a thermoelectric material and device laboratory of Wuhan university of science and technology invents an all-solid-state energy conversion refrigeration device (ZL 202011207036.9) based on thermoelectric magnetic coupling, and the refrigeration mechanism of the device is as follows: the motor drives the thermoelectric magnetic refrigeration element to different working areas, direct currents in different directions are applied, and the thermoelectric effect and the magnetocaloric effect are utilized to enable the thermoelectric magnetic refrigeration element to circularly realize a heat absorption function and a heat release function; the specific process is as follows: in the heat release working area, the thermoelectric magnetic refrigeration element applying the forward current actively releases heat by utilizing a thermoelectric effect and assists in releasing heat by utilizing a magnetocaloric effect; after the heat release process is finished, the step motor is operated, the thermoelectric magnetic refrigeration element is rotated to a heat absorption working area, and the thermoelectric magnetic refrigeration element applying reverse current actively absorbs heat by utilizing a thermoelectric effect and assists in absorbing heat by utilizing a magnetocaloric effect; the operation is repeated in such a way, so that the refrigeration of the heat absorption working area is realized.

However, in such a refrigeration device, the motor operation control and the current commutation control must be synchronously integrated, and the existing electromechanical control method cannot meet the requirements of the refrigeration device. .

Disclosure of Invention

The invention aims to provide an electromechanical control system and method of an all-solid-state energy conversion refrigerating device based on thermal electromagnetic coupling, which have strong universality and high flexibility.

The technical scheme adopted by the invention is as follows: an electromechanical control system of an all-solid-state energy conversion refrigerating device comprises a synchronous control upper computer, a current direction control unit, a motor drive control unit and a direct-current power supply, wherein the synchronous upper computer is respectively connected with the current direction control unit and the motor drive control unit and is used for sending control instructions to the two units; the current direction control unit is connected with a thermoelectric magnetic refrigeration element of the all-solid-state energy conversion refrigeration device and applies current to the thermoelectric magnetic refrigeration element; the motor driving control unit is connected with a stepping motor of the all-solid-state energy conversion refrigerating device and drives the stepping motor to rotate; and the direct current power supply is respectively connected with the current direction control module and the motor drive control unit and is used for current transmission of the two units.

According to the scheme, the current direction control unit comprises se:Sub>A PLC-A module and se:Sub>A current reversing control module connected with the PLC-A, the PLC-A module is connected with the synchronous upper computer, and the current reversing control module is connected with the thermoelectric magnetic refrigeration element.

According to the scheme, the control method of the current direction control unit comprises the following steps: se:Sub>A user sets parameters of the PLC-A module, the PLC-A module reads variables to complete variable initialization, analyzes se:Sub>A current direction instruction sent by an upper computer, and determines the current direction and the current magnitude according to the heat absorption and heat release functions of the thermoelectric magnetic refrigeration element; the PLC-A module drives the current reversing control module to apply forward or reverse current to the thermoelectric magnetic refrigeration element according to the determined current magnitude to realize the heat absorption or heat release function; meanwhile, the PLC-A module feeds back temperature signals at two ends of the thermal electromagnetic refrigeration element to the upper computer in real time, and the current supply direction control unit judges whether the operation is finished or continuously repeats the operation flow.

According to the scheme, the motor drive control unit comprises a PLC-B module and a motor drive control module connected with the PLC-B; the PLC-B module is connected with the synchronous upper computer, and the motor driving control module is connected with the stepping motor.

According to the scheme, the control method of the motor drive control unit comprises the following steps: a user firstly sets parameters of a PLC-B module, the PLC-B module reads variable values to complete variable initialization, the PLC-B module analyzes a motor rotation direction instruction sent by an upper computer, and the rotation angle is determined according to the forward rotation and reverse rotation functions of a stepping motor; the PLC-B module drives the motor driving control module, and sends a rotation instruction to the stepping motor according to the determined angle, so that forward rotation or reverse rotation is realized; meanwhile, the PLC-B module feeds back a station signal of the thermal electromagnetic refrigeration element to the upper computer, and the power supply motor rotation unit judges whether the operation is finished or continuously repeats the operation flow.

The invention also provides a control method using the control system, which comprises the following steps:

step one, starting a power switch of the all-solid-state energy conversion refrigerating device, inputting and storing process setting parameters on a synchronous upper computer;

step two, the synchronous upper computer reads the procedure setting parameters and sends a station inquiring instruction to judge whether the thermoelectric magnetic refrigeration element is at the initial station, and if not, the station is adjusted and judged again; if the system is started at the initial station, further judging whether the system is started, if not, starting the system and judging again, and if so, carrying out the next step;

after the system is started, respectively downloading step parameters set by the process to se:Sub>A PLC-A module and se:Sub>A PLC-B module, simultaneously starting control flows of the PLC-A module and the PLC-B module after the preparation work is finished, respectively sending se:Sub>A current instruction to the PLC-A module by se:Sub>A synchronous upper computer, and sending se:Sub>A motor instruction to the PLC-B module;

the PLC-A module confirms the current transmission state and executes se:Sub>A current direction control unit program, positive current is applied to the two refrigeration elements entering the magnetic field heat insulation magnetization, the heat is actively dissipated at the hot end by using the Peltier effect, the heat is dissipated at the hot end in an auxiliary manner by using the magnetocaloric effect, and the whole device dissipates heat to the outside through the hot end heat exchanger so as to reduce the temperature of the two refrigeration elements to the room temperature; applying reverse current to the other two refrigeration elements which leave the magnetic field and are subjected to heat insulation and demagnetization, assisting in absorbing heat at the cold end by utilizing the magnetocaloric effect, absorbing heat from the outside through a cold end heat exchanger, and raising the temperature of the two refrigeration elements to room temperature; the PLC-A module acquires the temperature and the current value at two ends of the refrigerating element and feeds the temperature and the current value back to the synchronous upper computer;

step five, the PLC-B module confirms the running state of the motor and executes a motor rotation control unit program, so that the stepping motor drives the thermal electromagnetic refrigeration element to rotate 90 degrees around a concentric circle, and the refrigeration element after the excitation flow leaves a magnetic field to remove the magnetic field and the refrigeration element after the demagnetization flow enters the magnetic field to perform the excitation flow; the PLC-B module acquires the station information of the refrigeration element and feeds the station information back to the upper computer;

step six, the synchronous upper computer repeats the step one to the step five, judges whether the testing step completes the program, if not, repeats the control flow of the PLC-A module and the PLC-B module, and if so, stops the current reversing control module and the motor driving control module;

and seventhly, storing the station information, the current direction, the current value, the voltage value, the resistance value and the temperature values at two ends of the thermoelectric magnetic refrigeration element into a result database.

The invention has the beneficial effects that: the invention distributes different specific process parameters to the current direction control unit and the motor driving control unit respectively through the synchronous control upper computer, and sends different control instructions respectively, so that the thermal electromagnetic refrigeration element can reach a required working area according to a set time period under the driving of the stepping motor, and the required working current direction and magnitude are applied to the thermal electromagnetic refrigeration element; the control system has high universality and flexibility and low development cost, and can be directly applied to all-solid-state energy conversion refrigeration devices based on thermoelectric magnetic coupling or other mechanical fields with the requirements.

Drawings

Fig. 1 is a block diagram of an electromechanical control system according to an embodiment of the present invention.

Fig. 2 is a flowchart of the current direction control unit in the present embodiment.

Fig. 3 is a flowchart of the motor rotation control unit in the present embodiment.

Fig. 4 is a first schematic view of the operation principle of the thermal electromagnetic cooling element in this embodiment.

Fig. 5 is a schematic view illustrating a second working principle of the thermal electromagnetic cooling element in this embodiment.

Fig. 6 is a schematic view of the working principle of the all-solid-state energy conversion refrigerating apparatus in this embodiment.

Fig. 7 is a flowchart of the overall operation procedure of the present embodiment.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the examples of the present invention, and it is obvious that the described embodiments are only one sub-embodiments of the present invention, and not all embodiments. All other embodiments obtained by a person skilled in the art without making any inventive step are within the scope of protection of the present invention.

The electromechanical control system of the all-solid-state energy conversion refrigerating device shown in fig. 1 comprises a synchronous control upper computer, a current direction control unit, a motor drive control unit and a direct-current power supply, wherein the synchronous upper computer is respectively connected with the current direction control unit and the motor drive control unit and is used for sending control instructions to the two units; the current direction control unit is connected with a thermoelectric magnetic refrigeration element of the all-solid-state energy conversion refrigeration device and applies current to the thermoelectric magnetic refrigeration element; the motor driving control unit is connected with a stepping motor of the all-solid-state energy conversion refrigerating device and drives the stepping motor to rotate; and the direct current power supply is respectively connected with the current direction control module and the motor drive control unit and is used for current transmission of the two units.

Preferably, the current direction control unit comprises se:Sub>A PLC-A module and se:Sub>A current reversing control module connected with the PLC-A, and the current reversing control module is connected with the thermoelectric magnetic refrigeration element; the PLC-A module is also connected with the synchronous upper computer and used for receiving and analyzing se:Sub>A current direction instruction sent by the synchronous upper computer, and determining the current direction and the current magnitude according to the heat absorption and heat release functions of the thermal electromagnetic refrigeration element of the all-solid-state energy conversion refrigeration device, and then sending the current direction and magnitude instruction to the current direction control module, so that the current direction control module applies forward or reverse current required for realizing the heat absorption or heat release functions to the thermal electromagnetic refrigeration element according to the determined current magnitude, and simultaneously the PLC-A module feeds back temperature signals at two ends of the thermal electromagnetic refrigeration element to the synchronous upper computer in real time.

As shown in fig. 2, the specific control flow of the current direction control unit is as follows: se:Sub>A user sets parameters of the PLC-A module (the parameters comprise the current direction and the current magnitude applied to the thermo-electromagnetic refrigerating element, wherein the current direction changes along with different working areas of the element), the PLC-A module reads variables to complete variable initialization (the variables are current state values of the current direction and the current magnitude of the thermo-electromagnetic refrigerating element), analyzes se:Sub>A current direction instruction sent by an upper computer, and determines the current direction and the current magnitude according to the heat absorption and heat release functions of the thermo-electromagnetic refrigerating element; the PLC-A module drives the current reversing control module to apply forward or reverse current to the thermoelectric magnetic refrigeration element according to the determined current magnitude to realize the heat absorption or heat release function; meanwhile, the PLC-A module feeds back temperature signals at two ends of the thermal electromagnetic refrigeration element to the upper computer in real time, and the current supply direction control unit judges whether the operation is finished or continuously repeats the operation flow.

In the invention, the motor drive control unit comprises a PLC-B module and a motor drive control module connected with the PLC-B, and the motor drive control module is connected with a stepping motor; the PLC-B module is also connected with the synchronous upper computer and used for receiving and analyzing a motor rotation direction instruction sent by the upper computer, calculating and determining the rotation angle according to the forward and reverse rotation functions of the stepping motor, and sending a control instruction to the motor driving control module, so that the motor driving control module drives the stepping motor to rotate forward or reversely according to the determined angle, and meanwhile, the PLC-B module feeds back a station signal of the thermoelectric electromagnetic refrigeration element to the synchronous upper computer in real time.

As shown in fig. 3, the specific control flow of the motor drive control unit is as follows: a user firstly sets parameters of a PLC-B module (the parameters comprise the positive and negative rotation directions and the rotation angle of a stepping motor during working), the PLC-B module reads variable values to complete variable initialization (the variable is the current state value of the stepping motor and is positioned before starting), so that the PLC-B module can analyze a motor rotation direction instruction sent by an upper computer and determine the rotation angle according to the positive and negative rotation functions of the stepping motor; the PLC-B module drives the motor driving control module, and sends a rotation instruction to the stepping motor according to the determined angle, so that forward rotation or reverse rotation is realized; meanwhile, the PLC-B module feeds back a station signal of the thermal electromagnetic refrigeration element to the upper computer, and the power supply motor rotation unit judges whether the operation is finished or continuously repeats the operation flow.

In the invention, the total running program of the whole system is controlled by the synchronous upper computer, the synchronous upper computer can self-diagnose the running condition of the system while setting the working procedure parameters of the whole system, and sends instructions to the lower computers such as the current direction control unit, the motor driving control unit, the thermo-electromagnetic refrigeration element, the stepping motor and the like through the synchronous upper computer, and each lower computer feeds back the running condition of the lower computer to the synchronous upper computer in real time, thereby ensuring the synchronization, the cooperation and the integration of the motor running control and the current transmission control.

Examples

The all-solid-state energy refrigeration conversion device is the prior art, and as shown in fig. 4, a thermoelectric magnetic refrigeration element of the all-solid-state energy refrigeration conversion device includes a P-type thermoelectric magnetic material 3, an N-type thermoelectric magnetic material 4, an outer ring electrode 1, an inner ring electrode 2, a direct current power supply 6, and a lead 5, where the P-type thermoelectric magnetic material 3 and the N-type thermoelectric magnetic material 4 are thermoelectric magnetic materials with a gradient composite structure or a uniform composite structure, which are obtained by compounding the P-type thermoelectric material and the N-type thermoelectric material with the magnetocaloric material, respectively. The N-type thermoelectric magnetic refrigerating piece 4 is connected with the outer ring of the P-type thermoelectric magnetic refrigerating piece 3 through an outer ring electrode 1, and the outer ring electrode 1 is an arc red copper electrode; the inner rings of the N-type thermal electromagnetic refrigerating piece 4 and the P-type thermal electromagnetic refrigerating piece 3 are respectively provided with an inner ring electrode 2, and the inner ring electrodes 2 are respectively connected with the positive electrode and the negative electrode of a direct current power supply 6 through leads 5. While the heat is absorbed by the heat absorption device or actively, the heat is dissipated or absorbed by the aid of the magnetocaloric effect. When the thermo-electromagnetic refrigerating element is in a magnetic field, a working station, namely an initial station, forward current flows in from a P-type thermo-electromagnetic material of the thermo-electromagnetic refrigerating element, active heat dissipation is performed by using a thermo-electric effect, auxiliary heat dissipation is performed by using the thermo-magnetic effect, an outer ring is a hot end, an inner ring is a cold end, and as shown in fig. 4, the hot end of the thermo-electromagnetic refrigerating element dissipates heat and the cold end absorbs heat; when the thermo-electromagnetic refrigerating element leaves the magnetic field, a reverse current flows in from the N-type thermo-electromagnetic material of the thermo-electromagnetic refrigerating element, active heat absorption is performed by using the thermo-electric effect, auxiliary heat absorption is performed by using the magneto-thermal effect, the outer ring is a cold end, the inner ring is a hot end, and as shown in fig. 5, the cold end of the thermo-electromagnetic refrigerating element absorbs heat and the hot end dissipates heat. Other structures of the all-solid-state energy refrigeration conversion device are the prior art, and are not described herein again.

In the all-solid-state energy conversion refrigerating device based on the thermoelectric magnetic coupling shown in fig. 5, the thermoelectric magnetic refrigerating elements are fixed on the chassis, and the chassis 7 can rotate around a concentric circle by 90 degrees in a reciprocating manner under the driving of the stepping motor, so that the two thermoelectric magnetic refrigerating elements can enter and leave a heat absorption working area or a heat dissipation working area in a reciprocating manner. The working principle of the whole device is as follows: the stepping motor rotates forwards by 90 degrees, the thermoelectric magnetic refrigeration element enters a magnetic field and is positioned in a heat dissipation working area to apply forward current, the thermoelectric effect is used for actively dissipating heat, and the magnetocaloric effect is used for assisting in dissipating heat; after the heat dissipation process is finished, the stepping motor rotates in the reverse direction for 90 degrees, the thermoelectric magnetic refrigeration element leaves the magnetic field and is positioned in a heat absorption working area, reverse current is applied, the thermoelectric effect is used for actively absorbing heat, and the magnetocaloric effect is used for assisting in absorbing heat; the operation is repeated in such a way, so that the refrigeration of the heat absorption working area is realized. Before the control system is adopted to control the thermoelectric coupling-based all-solid-state energy conversion refrigerating device, firstly, procedure setting parameters, namely subsequent control programs, need to be input in a synchronous upper computer; the step parameters in the control method are the respective control flows behind the PLC-A module and the PLC-B module.

As shown in fig. 6, a control method for an all-solid-state energy conversion refrigeration device based on thermoelectric magnetic coupling specifically includes:

step one, starting a power switch of the all-solid-state energy conversion refrigerating device, inputting and storing process setting parameters on a synchronous upper computer;

step two, the synchronous upper computer reads the procedure setting parameters and sends a station inquiring instruction to judge whether the thermoelectric magnetic refrigeration element is at the initial station, and if not, the station is adjusted and judged again; if the system is started at the initial station, further judging whether the system is started, if not, starting the system and judging again, and if so, carrying out the next step;

step three, after se:Sub>A system is started, downloading step parameters set by the process to se:Sub>A PLC-A module and se:Sub>A PLC-B module respectively, starting control flows of the PLC-A module and the PLC-B module simultaneously after the preparation work is finished, sending current instructions (including the direction and the magnitude of current) to the PLC-A module and sending motor instructions (including the rotation direction and the angle of se:Sub>A motor) to the PLC-B module respectively by se:Sub>A synchronous upper computer;

the PLC-A module confirms the current transmission state and executes se:Sub>A current direction control unit program, positive current is applied to the two refrigeration elements entering the magnetic field heat insulation magnetization, the heat is actively dissipated at the hot end by using the Peltier effect, the heat is dissipated at the hot end in an auxiliary manner by using the magnetocaloric effect, and the whole device dissipates heat to the outside through the hot end heat exchanger so as to reduce the temperature of the two refrigeration elements to the room temperature; applying reverse current to the other two refrigeration elements which leave the magnetic field and are subjected to heat insulation and demagnetization, assisting in absorbing heat at the cold end by utilizing the magnetocaloric effect, absorbing heat from the outside through a cold end heat exchanger, and raising the temperature of the two refrigeration elements to room temperature; the PLC-A module acquires the temperature and the current value at two ends of the refrigerating element and feeds the temperature and the current value back to the synchronous upper computer;

step five, the PLC-B module confirms the running state of the motor and executes a motor rotation control unit program, so that the stepping motor drives the thermal electromagnetic refrigeration element to rotate 90 degrees around a concentric circle, and the refrigeration element after the excitation flow leaves a magnetic field to remove the magnetic field and the refrigeration element after the demagnetization flow enters the magnetic field to perform the excitation flow; the PLC-B module acquires station information of the refrigeration element and feeds the station information back to the upper computer;

step six, se:Sub>A synchronous upper computer is modified and tested, the step n = n +1 (the step three-step five is se:Sub>A test period, the modified test step n = n +1 means that the system finishes se:Sub>A test period and prepares to carry out the next test period), whether the whole test step is finished or not is judged, if not, the step three-step five is repeated to carry out the next test period, namely the control flow of the PLC-A module and the PLC-B module, and if so, the current reversing control module and the motor driving control module are stopped;

and seventhly, storing the station information, the current direction, the current value, the voltage value, the resistance value and the temperature values at two ends of the thermoelectric magnetic refrigeration element into a result database.

It should be noted that, although the present invention has been described in detail with reference to the embodiments, it will be apparent to those skilled in the art that modifications, equivalents, improvements and the like can be made in the embodiments or some of the features of the embodiments without departing from the spirit and the principle of the present invention.

Claims (2)

1. An electromechanical control system of an all-solid-state energy conversion refrigerating device is characterized by comprising a synchronous control upper computer, a current direction control unit, a motor drive control unit and a direct-current power supply, wherein the synchronous upper computer is respectively connected with the current direction control unit and the motor drive control unit and is used for sending control instructions to the two units; the current direction control unit is connected with a thermoelectric magnetic refrigeration element of the all-solid-state energy conversion refrigeration device and applies current to the thermoelectric magnetic refrigeration element; the motor driving control unit is connected with a stepping motor of the all-solid-state energy conversion refrigerating device and drives the stepping motor to rotate; the direct current power supply is respectively connected with the current direction control module and the motor drive control unit and is used for current transmission of the two units; the current direction control unit comprises se:Sub>A PLC-A module and se:Sub>A current reversing control module connected with the PLC-A, the PLC-A module is connected with the synchronous upper computer, and the current reversing control module is connected with the thermoelectric magnetic refrigeration element; the control method of the current direction control unit comprises the following steps: se:Sub>A user sets parameters of the PLC-A module, the PLC-A module reads variables to complete variable initialization, analyzes se:Sub>A current direction instruction sent by an upper computer, and determines the current direction and the current magnitude according to the heat absorption and heat release functions of the thermoelectric magnetic refrigeration element; the PLC-A module drives the current reversing control module to apply forward or reverse current to the thermoelectric magnetic refrigeration element to realize the heat absorption or heat release function; meanwhile, the PLC-A module feeds back temperature signals at two ends of the thermal electromagnetic refrigeration element to the upper computer in real time, and the current supply direction control unit judges whether the operation is finished or continuously repeats the operation flow; the motor drive control unit comprises a PLC-B module and a motor drive control module connected with the PLC-B; the PLC-B module is connected with the synchronous upper computer, and the motor driving control module is connected with the stepping motor; the control method of the motor drive control unit comprises the following steps: a user firstly sets parameters of a PLC-B module, the PLC-B module reads variable values to complete variable initialization, the PLC-B module analyzes a motor rotating direction instruction sent by an upper computer, and the size of a rotating angle is determined according to forward and reverse rotation functions of a stepping motor; the PLC-B module drives the motor driving control module to send a rotation instruction to the stepping motor so as to realize forward rotation or reverse rotation; meanwhile, the PLC-B module feeds back a station signal of the thermal electromagnetic refrigeration element to the upper computer, and the power supply motor rotation unit judges whether the operation is finished or continuously repeats the operation flow.

2. A control method using the control system of claim 1, the method comprising:

step one, starting a power switch of the all-solid-state energy conversion refrigerating device, inputting and storing process setting parameters on a synchronous upper computer;

step two, the synchronous upper computer reads the procedure setting parameters and sends a station inquiring instruction to judge whether the thermoelectric magnetic refrigeration element is at the initial station, and if not, the station is adjusted and judged again; if the system is started at the initial station, further judging whether the system is started, if not, starting the system and judging again, and if so, carrying out the next step;

after the system is started, respectively downloading step parameters set by the process to se:Sub>A PLC-A module and se:Sub>A PLC-B module, simultaneously starting control flows of the PLC-A module and the PLC-B module after the preparation work is finished, respectively sending se:Sub>A current instruction to the PLC-A module by se:Sub>A synchronous upper computer, and sending se:Sub>A motor instruction to the PLC-B module;

the PLC-A module confirms the current transmission state and executes se:Sub>A current direction control unit program, positive current is applied to the two refrigeration elements entering the magnetic field heat insulation magnetization, the heat is actively dissipated at the hot end by using the Peltier effect, the heat is dissipated at the hot end in an auxiliary manner by using the magnetocaloric effect, and the whole device dissipates heat to the outside through the hot end heat exchanger so as to reduce the temperature of the two refrigeration elements to the room temperature; applying reverse current to the other two refrigeration elements which leave the magnetic field and are subjected to adiabatic demagnetization, assisting in absorbing heat at the cold end by using the magnetocaloric effect, and absorbing heat from the outside through a cold end heat exchanger by the whole device so as to enable the temperatures of the two refrigeration elements to rise to room temperature; the PLC-A module acquires the temperature and the current value at two ends of the refrigeration element and feeds the temperature and the current value back to the synchronous upper computer;

step five, the PLC-B module confirms the running state of the motor and executes a motor rotation control unit program, so that the stepping motor drives the thermal electromagnetic refrigeration element to rotate 90 degrees around a concentric circle, and the refrigeration element after the excitation flow leaves a magnetic field to remove the magnetic field and the refrigeration element after the demagnetization flow enters the magnetic field to perform the excitation flow; the PLC-B module acquires the station information of the refrigeration element and feeds the station information back to the upper computer;

step six, the synchronous upper computer repeats the step one to the step five, judges whether the testing step completes the program, if not, repeats the control flow of the PLC-A module and the PLC-B module, and if so, stops the current reversing control module and the motor driving control module;

and seventhly, storing the station information, the current direction, the current value, the voltage value, the resistance value and the temperature values at two ends of the thermoelectric magnetic refrigeration element into a result database.

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