Power adjusting method and system of electric heater

Abstract

The invention discloses a power adjusting method and system for an electric heater, and the method is used for controlling a power adjusting device corresponding to the electric heater to work based on a switching-on cycle number, and comprises a step of correcting a continuous switching-on cycle number, i.e., when the adjustment judgment time corresponding to a current work period is reached, the power adjusting device is started; based on a difference value between the target electrical measurement and the accumulated electrical measurement, determining a connection cycle number corresponding to the next work cycle; the method for determining the second cycle number is characterized in that the connection cycle number corresponding to the current work cycle is recorded as the first cycle number, the connection cycle number corresponding to the next work cycle is recorded as the second cycle number, and the method for determining the second cycle number comprises the following steps: determining accumulated time data; determining a target electric quantity based on the accumulated time data and a power regulation target value corresponding to the target power regulation device; acquiring an accumulated electric quantity corresponding to the accumulated time data; calculating a difference value between the target electric quantity and the accumulated electric quantity; a second number of cycles is determined based on the difference and the first number of cycles. According to the invention, the power can be quickly and accurately adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of power regulation, and in particular to a power regulation technology for an electric heater. Background Art

[0002] Renewable energy sources such as wind power and solar power are characterized by volatility, intermittency, and randomness, and require energy storage as a buffer to achieve a new type of continuous, stable, and dispatchable power system.

[0003] The power regulation system controls the power of the electric heater as a controllable load, realizing energy storage and buffering in the fields of thermal power frequency regulation and abandoned power consumption. However, the current thyristor-based power regulation devices are mostly used for temperature control of industrial electric heating furnaces, which are not suitable for power regulation of such electric heaters that need to respond quickly to changes in grid ratings. Summary of the invention

[0004] The power regulation scheme of the electric heater disclosed in the prior art has the defect that it is difficult to quickly respond to the change of the power grid frequency.

[0005] In order to solve the above technical problems, the present invention is solved by the following technical solutions:

[0006] A power regulation method for an electric heater, for controlling the operation of a power regulating device corresponding to the electric heater based on a switching frequency, and determining the switching frequency corresponding to the next working cycle based on the difference between a target power amount and an accumulated power amount when the adjustment determination time corresponding to the current working cycle is reached;

[0007] The connected frequency corresponding to the current working cycle is recorded as the first frequency, and the connected frequency corresponding to the next working cycle is recorded as the second frequency. The method for determining the second frequency includes the following steps:

[0008] Determine cumulative time data;

[0009] Determine a target amount of electricity based on the accumulated time data and a power regulation target value corresponding to the target power regulation device;

[0010] Obtaining the accumulated electricity amount corresponding to the accumulated time data;

[0011] Calculating a difference between the target electric quantity and the accumulated electric quantity;

[0012] When the obtained difference reaches the error threshold and the accumulated electricity amount is greater than the target electricity amount, the first frequency is reduced to generate the second frequency, and the accumulated time data is reset at the beginning of the next working cycle;

[0013] When the obtained difference reaches the error threshold and the accumulated electricity amount is less than the target electricity amount, the first frequency is increased to generate the second frequency, and the accumulated time data is reset at the beginning of the next working cycle;

[0014] When the obtained difference does not reach the error threshold, the first frequency is used as the second frequency.

[0015] As an implementable method, a method for obtaining the basic frequency corresponding to the power regulation target value is:

[0016] Based on the power regulation target value corresponding to the target electric heater and the average line voltage of the first power supply, and the single-phase resistance value of the target electric heater, the basic frequency is determined, and the calculation formula is:

[0017]

[0018] in:

[0019] n represents the basic frequency;

[0020] P represents the power regulation target value;

[0021] R represents the single-phase resistance value of the target electric heater;

[0022] U represents the average line voltage of the first power supply;

[0023] T represents the reference time, which is used to indicate the duration corresponding to a working cycle.

[0024] As an implementable method, the method for obtaining the error threshold is:

[0025] Determine the corresponding power supply average line voltage based on the adjustment determination time to obtain a second power supply average line voltage;

[0026] A corresponding error threshold is calculated based on the second power supply average line voltage, the single-phase resistance value of the target electric heater, and a preset error parameter.

[0027] As an implementable method:

[0028] Divide the reference time according to the number of devices to be controlled to obtain a number of control time points corresponding to the number of devices to be controlled, wherein the number of devices to be controlled represents the number of power regulating devices to be controlled, and the reference time represents the duration corresponding to a working cycle;

[0029] A power regulating signal is sent to a power regulating device to be controlled at each control time point, and a stop signal is sent to the power regulating device to be controlled according to a first frequency corresponding to the power regulating device to be controlled.

[0030] A power regulation system for an electric heater, used for controlling the operation of a power regulation device corresponding to the electric heater based on the frequency of the switch-on, comprising:

[0031] The PLC is connected to an external DCS system signal and is used to receive a power adjustment target value corresponding to the electric heater issued by the external DCS system;

[0032] A power regulating device corresponding one to one with the electric heater, the power regulating device being connected to the PLC signal;

[0033] A measuring device corresponding to each of the electric heaters, the measuring device being connected to the PLC signal and used to send voltage data, current data and electricity measurement data of the corresponding electric heater to the PLC;

[0034] The PLC is used to execute any one of the above-mentioned methods for regulating the power of the electric heater.

[0035] As an implementable method:

[0036] The power regulating device has an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal and a voltage output terminal, and the voltage output terminal is coupled to the corresponding electric heater;

[0037] The power regulating device also includes a first series branch, a second series branch, a third series branch, a trigger control circuit and an overvoltage protection circuit;

[0038] One end of the first series branch is coupled to the A-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively;

[0039] One end of the second series branch is coupled to the B-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively;

[0040] One end of the third series branch is coupled to the C-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively;

[0041] The first series branch and the third series branch are provided with thyristor valve groups;

[0042] The trigger control circuit is connected to the PLC signal and is also coupled to each thyristor valve group respectively, for receiving the power regulation signal sent by the PLC, and based on the power regulation signal, when the AB line voltage or the BC line voltage passes through zero, controlling the corresponding thyristor valve group to turn on, and when the A phase voltage or the C phase voltage passes through zero, controlling the corresponding thyristor valve group to commutate.

[0043] As an implementable method:

[0044] The trigger control circuit in the power regulating device includes a connected bidirectional thyristor trigger and a voltage transformer, and the voltage transformer is used to detect the AB line voltage and the BC line voltage;

[0045] Note: When the line voltage is known, those skilled in the art can easily calculate the corresponding phase voltage based on existing technology;

[0046] The measuring device comprises:

[0047] A first current transformer, a second current transformer, a third current transformer and a collector, wherein the collector is coupled to the first current transformer, the second current transformer, the third current transformer and the voltage transformer respectively, and the collector is also connected to the PLC signal;

[0048] The first current transformer is used to measure the loop phase current corresponding to the first series branch in the corresponding power regulation device;

[0049] The second current transformer is used to measure the loop phase current corresponding to the third series branch in the corresponding power regulation device;

[0050] The third current transformer is used to measure zero-sequence current;

[0051] The collector is used to send the received voltage data and current data to the PLC, and is also used to calculate the electrical quantity based on the received voltage data and current data, obtain the corresponding unit measurement electrical quantity, and send the unit measurement electrical quantity to the PLC.

[0052] As an implementable embodiment, the power regulating device further includes a charged display branch corresponding to each series branch one by one;

[0053] The power-on display branch has an indicator light. One end of the power-on display branch is grounded, and the other end is coupled to the corresponding series branch. When the corresponding series branch is turned on, the indicator light is on.

[0054] As an implementable method:

[0055] Each series branch is provided with a vacuum contactor, and the vacuum contactor is connected to the PLC signal;

[0056] The first series branch and the third series branch are also provided with fast fuses.

[0057] As an implementable method:

[0058] The power regulating device also includes a heat dissipation system;

[0059] The heat dissipation system is connected to the PLC signal.

[0060] The present invention has significant technical effects due to the adoption of the above technical solution:

[0061] The present invention corrects the number of continuous conduction cycles corresponding to the next working cycle by comparing the target electricity quantity corresponding to the accumulated time data with the accumulated electricity quantity, thereby realizing fast and accurate power regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0063] Figure 1 It is a schematic diagram of a flow chart of correcting the number of continuous conduction cycles corresponding to the next working cycle in one embodiment of the present invention;

[0064] Figure 2 is a schematic diagram of module connections of a power regulation system for an electric heater in one embodiment of the present invention;

[0065] Figure 3 It is a circuit connection diagram of a power regulation system of an electric heater in one embodiment of the present invention. DETAILED DESCRIPTION

[0066] The present invention is further described in detail below in conjunction with embodiments. The following embodiments are for explanation of the present invention but the present invention is not limited to the following embodiments.

[0067] A power regulation method for an electric heater, for controlling the operation of a power regulation device corresponding to the electric heater based on the frequency of the switch-on operation, comprises the following steps:

[0068] S100, receiving power adjustment target value;

[0069] Taking a molten salt electric heater as an example, the molten salt electric heater corresponding to the power adjustment target value is used as a target electric heater, and the power adjustment device corresponding to the target electric heater is used as a target power adjustment device;

[0070] In this embodiment, an external DCS system (distributed control system) generates a power adjustment target value for the electric heater to be adjusted according to actual working conditions and sends it to the PLC. This is a prior art and will not be described in detail in this specification.

[0071] S200, obtaining the basic frequency corresponding to the power adjustment target value;

[0072] The basic frequency represents the frequency of continuous connection;

[0073] In this embodiment, the basic frequency is determined based on the power adjustment target value corresponding to the target electric heater and the average line voltage of the first power supply, as well as the single-phase resistance value of the target electric heater. The calculation formula is:

[0074]

[0075] in:

[0076] n represents the basic frequency;

[0077] P represents the power regulation target value, in W;

[0078] R represents the single-phase resistance value of the target electric heater, in Ω;

[0079] U represents the average line voltage of the first power supply, in V, which is the average value of any line voltage within a preset time range. Those skilled in the art can set the calculation rules by themselves, such as setting the time range or number of samples involved in the average calculation;

[0080] T represents the reference time, the unit is s, and is used to indicate the duration corresponding to a working cycle.

[0081] S300, determining a first frequency, and controlling the operation of the target power regulating device in the current working cycle based on the first frequency;

[0082] The connected frequency corresponding to the current working cycle is recorded as the first frequency, and the connected frequency corresponding to the next working cycle is recorded as the second frequency;

[0083] The second frequency generated in the previous working cycle is used as the first frequency of the current working cycle, and the initial value of the first frequency is the basic frequency.

[0084] This embodiment controls the operation of the target power regulating device based on the frequency zero-crossing technology, that is, generates a power regulating signal and sends it to the target power regulating device, so that the corresponding phase path in the target power regulating device passes through zero and is turned on; generates a stop signal based on the first frequency and sends it to the target power regulating device, so that the corresponding phase path of the target power regulating device is turned off.

[0085] S400, determining the second frequency;

[0086] When the adjustment determination time corresponding to the current working cycle is reached, the number of switching cycles corresponding to the next working cycle is determined based on the difference between the target power amount and the accumulated power amount;

[0087] Those skilled in the art can adjust the judgment time according to actual needs, for example, it can be set to the time corresponding to t seconds before the end of the current working cycle;

[0088] The specific steps include:

[0089] S410, determining accumulated time data;

[0090] The accumulated time data is used to indicate whether the actual power meets the time range corresponding to the power regulation target value;

[0091] S420, determining a target electricity amount based on the accumulated time data and a power regulation target value corresponding to a target power regulation device;

[0092] That is, a theoretical value of the target electric heater corresponding electric power amount is calculated based on the power adjustment target value and the accumulated time data.

[0093] S430, obtaining the accumulated electricity amount corresponding to the accumulated time data;

[0094] Based on the parameters of the target electric heater, and the corresponding parameters such as voltage and current, those skilled in the art can calculate the corresponding electricity consumption within the accumulated time data based on the existing technology, so it will not be described in detail.

[0095] S440, calculating the difference between the target electric quantity and the accumulated electric quantity, and adjusting the first frequency based on the difference to obtain a corresponding second frequency;

[0096] S441, when the obtained difference reaches the error threshold and the accumulated electricity amount is greater than the target electricity amount, reducing the first frequency, generating the second frequency, and resetting the accumulated time data at the beginning of the next working cycle;

[0097] That is, when |Q2-Q1|≥E and Q2-Q1>0, let n2=n1-m;

[0098] in:

[0099] Q1 represents the target electricity quantity;

[0100] Q2 represents the accumulated electricity quantity;

[0101] E represents the error threshold;

[0102] n1 represents the first cycle number;

[0103] n2 represents the second frequency;

[0104] m represents the unit adjustment amount, m is a positive integer, and in this embodiment, m=1.

[0105] S442: when the obtained difference reaches the error threshold and the accumulated electricity amount is less than the target electricity amount, increase the first frequency to generate the second frequency, and reset the accumulated time data at the beginning of the next working cycle;

[0106] That is, when |Q2-Q1|≥E and Q2-Q1<0, let n2=n1+m.

[0107] S443: When the obtained difference does not reach the error threshold, the first frequency is used as the second frequency, and the time is continued to be accumulated based on the accumulated time data.

[0108] That is, |Q2-Q1|<E, n2=n1.

[0109] This embodiment determines the number of continuous conduction cycles n within the reference time based on the power regulation target value, and the PLC compares the difference between the expected power and the actual power according to a preset rule to correct the number of continuous conduction cycles n, thereby achieving fast and accurate power regulation.

[0110] In this embodiment, the error threshold E is a dynamic value, and the calculation method is as follows:

[0111] Determine the corresponding power supply average line voltage based on the adjustment determination time to obtain a second power supply average line voltage;

[0112] The average line voltage of the second power supply is the same as the line corresponding to the average line voltage of the first power supply. Those skilled in the art can set the calculation time of the average line voltage of the second power supply by themselves, for example, using the entire time period corresponding to the accumulated time data as the statistical analysis period, or using the previous working cycle as the statistical analysis period, or using the previous cycle as the statistical analysis period. This specification does not make any detailed limitations on this.

[0113] A corresponding error threshold is calculated based on the second power supply average line voltage, the single-phase resistance value of the target electric heater, and a preset error parameter.

[0114] The calculation formula of the error threshold is:

[0115]

[0116] in:

[0117] U' represents the average line voltage of the second power supply;

[0118] R represents the single-phase resistance value of the target electric heater;

[0119] A is a preset error parameter, and those skilled in the art can set the error parameter according to actual needs. In this embodiment, A=50.

[0120] When the target power regulating device reaches the adjustment judgment time corresponding to the current working cycle, the number of connected cycles corresponding to the next working cycle is determined based on the difference between the target power amount and the accumulated power amount;

[0121] Furthermore, when there are multiple power regulating devices to be controlled:

[0122] Divide the reference time according to the number of devices to be controlled to obtain a number of control time points corresponding to the number of devices to be controlled, wherein the number of devices to be controlled represents the number of power regulating devices to be controlled, and the reference time represents the duration corresponding to a working cycle;

[0123] A power regulating signal is sent to a power regulating device to be controlled at each control time point, and a stop signal is sent to the power regulating device to be controlled according to a first frequency corresponding to the power regulating device to be controlled.

[0124] That is, the reference time T is divided into N equal parts according to the number N of devices to be controlled, and the corresponding power regulating devices are controlled to be turned on in different time periods to achieve coordinated control of multiple power regulating devices and reduce the fluctuation of the total power load when multiple electric heaters use electricity at the same time.

[0125] A power regulation system for an electric heater is used to control the operation of a power regulation device 200 corresponding to an electric heater 300 based on the frequency of the switch-on. Figure 2 As shown, including:

[0126] The PLC 100 is connected to an external DCS system signal and is used to receive a power adjustment target value corresponding to the electric heater 300 issued by the external DCS system;

[0127] A power regulating device 200 corresponding to each of the electric heaters 300 , wherein the power regulating device 200 is signal-connected to the PLC 100 ;

[0128] A measuring device 400 corresponding to each of the electric heaters 300 , the measuring device 400 being connected to the PLC 100 signal and used to send voltage data, current data and electricity measurement data of the corresponding electric heater 300 to the PLC 100 ;

[0129] The PLC 100 is used to execute the power regulation method of the electric heater 300 . In this embodiment, the electric heater 300 is a molten salt electric heater.

[0130] Reference Figure 3 , the power regulating device 200 has an A-phase voltage input terminal (denoted as A), a B-phase voltage input terminal (denoted as B), a C-phase voltage input terminal (denoted as C) and a voltage output terminal (denoted as O), and the voltage output terminal is coupled to the corresponding electric heater 300;

[0131] The power regulating device 200 further includes a first series branch, a second series branch, a third series branch, a trigger control circuit and an overvoltage protection circuit 220;

[0132] One end of the first series branch is coupled to the A-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit 220 respectively;

[0133] One end of the second series branch is coupled to the B-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit 220 respectively;

[0134] One end of the third series branch is coupled to the C-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit 220 respectively;

[0135] The first series branch and the third series branch are provided with a thyristor valve group 201;

[0136] In practical applications, the first series branch and the third series branch are further provided with a fast fuse 202 .

[0137] The trigger control circuit is connected to the PLC100 signal and is also coupled to each thyristor valve group 201 respectively, for receiving the power regulation signal sent by the PLC100, and based on the power regulation signal, when the AB line voltage or the BC line voltage passes through zero, controlling the corresponding thyristor valve group 201 to turn on, and when the A phase voltage or the C phase voltage passes through zero, controlling the corresponding thyristor valve group 201 to commutate.

[0138] At present, the power regulation device based on thyristor is mostly used for temperature control of industrial electric heating furnace, adopts phase shift control, and the power supply is a low-voltage power supply system with a neutral point directly grounded. This embodiment uses the principle that the vector sum of the two-phase current of the high-voltage ungrounded system is equal to the third phase, adopts zero-crossing control, and can realize the power regulation of the entire load by controlling any two phases of the three-phase symmetrical load.

[0139] In this embodiment, a group of thyristor valve groups 201 are installed in each of the A and C phases, and a low residual voltage overvoltage protector is used at the output end to realize phase-to-phase and relative overvoltage protection for the thyristor valve groups 201. During operation, the PLC100 intelligent controller controls the on and off of the thyristor valve groups 201, so that 0-100% power regulation of the load can be achieved.

[0140] The power regulation system of the electric heater provided by the present invention has a simple structure, low loss, small total heat generation of the power regulation device 200, a small number of devices, low equipment cost and high system efficiency.

[0141] Reference Figure 3, the trigger control circuit in the power regulating device 200 includes a connected bidirectional thyristor trigger 211 and a voltage transformer 212, and the voltage transformer 212 is used to detect the A phase voltage and the C phase voltage;

[0142] The bidirectional thyristor trigger 211 is connected to PLC100 and each thyristor valve group 201 respectively. After receiving the power regulation signal sent by PLC100, the bidirectional thyristor trigger 211 collects the voltage signal provided by the voltage transformer 212, and gives a trigger signal to control the corresponding thyristor valve group 201 to be turned on when the voltage of each phase passes through zero; after receiving the stop signal of the PLC100 intelligent controller, the trigger signal corresponding to each thyristor valve group 201 is canceled, so that each thyristor valve group 201 is naturally turned off when the current of that phase passes through zero.

[0143] In this embodiment, each voltage input terminal is connected to the voltage transformer 212 through a fuse 213 .

[0144] The measuring device 400 comprises:

[0145] A first current transformer 410, a second current transformer 420, a third current transformer 430 and a collector 440, wherein the collector 440 is coupled to the first current transformer 410, the second current transformer 420, the third current transformer 430 and the voltage transformer 212 respectively, and the collector 440 is also connected to the PLC 100 signal;

[0146] The first current transformer 410 is used to measure the loop phase current corresponding to the first series branch in the corresponding power regulation device 200;

[0147] The second current transformer 420 is used to measure the loop phase current corresponding to the third series branch in the corresponding power regulation device 200;

[0148] The third current transformer 430 is used to measure zero-sequence current;

[0149] The collector 440 is used to send the received voltage data and current data to the PLC100, and is also used to calculate the electricity quantity based on the received voltage data and current data, obtain the corresponding unit measurement electricity quantity, and send the unit measurement electricity quantity to the PLC100.

[0150] In this embodiment, the collector 440 collects and displays the power line voltage, loop phase current, and loop zero-sequence current through the A / D sampling module, and at the same time calculates the collected voltage and current to obtain the power and electrical quantity analog 4-20mA signal and sends it to the PLC100 intelligent controller.

[0151] In one embodiment, each series branch is provided with a vacuum contactor, and the vacuum contactor 203 is connected to the PLC100 signal;

[0152] In addition to controlling the vacuum contactor 203 to control the operation of the power regulation device 200 based on the instructions issued by the DCS system, PLC100 controls the vacuum contactor 203 to disconnect based on the current signal uploaded by the measurement system to achieve overcurrent protection. That is, when the loop phase current is greater than the rated overcurrent of the loop, PLC100 sends a switch signal to disconnect the vacuum contactor 203 to protect the thyristor valve group 201, cables, electric heaters and other equipment.

[0153] In one embodiment, the power regulating device 200 further includes a charged display branch 230 corresponding to each series branch one by one;

[0154] The power display branch 230 has an indicator light. One end of the power display branch 230 is grounded, and the other end is coupled to the corresponding series branch. When the corresponding series branch is turned on, the indicator light is on.

[0155] In practical applications, the electromagnetic lock of the cabinet can also be controlled based on the power display branch 230, that is, the electromagnetic lock is coupled to each power display branch 230, and when any power display branch 230 indicates power, the electromagnetic lock locks the cabinet door to prevent accidental entry into the powered interval.

[0156] As an implementable embodiment, the power regulating device 200 further includes a heat dissipation system 500;

[0157] The heat dissipation system 500 is connected to the PLC100 signal, and is used for temperature monitoring and heat dissipation of the power regulating device 200. The PLC100 controls the operation of the heat dissipation system 500 according to the startup status of the power regulating device 200. When the heat dissipation system 500 detects that the temperature exceeds the preset temperature limit, it provides a switch signal to the PLC100, and the PLC100 controls the power regulating device 200 to stop running.

[0158] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0159] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0160] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0161] The present invention is described with reference to the flowcharts and / or block diagrams of the method, terminal device (system), and computer program product according to the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0162] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0163] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0164] It should be noted that:

[0165] The "one embodiment" or "embodiment" mentioned in the specification means that the specific features, structures or characteristics described in conjunction with the embodiment are included in at least one embodiment of the present invention. Therefore, the phrases "one embodiment" or "embodiment" appearing in various places throughout the specification do not necessarily refer to the same embodiment.

[0166] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0167] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different. Any equivalent or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. The technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A power regulation method for an electric heater, for controlling the operation of a power regulation device corresponding to a target electric heater based on a switching frequency, characterized in that: When the adjustment determination time corresponding to the current working cycle is reached, the number of switching cycles corresponding to the next working cycle is determined based on the difference between the target power amount and the accumulated power amount; The connected frequency corresponding to the current working cycle is recorded as the first frequency, and the connected frequency corresponding to the next working cycle is recorded as the second frequency. The method for determining the second frequency includes the following steps: Determine cumulative time data; Determine a target amount of electricity based on the accumulated time data and a power regulation target value corresponding to the target power regulation device; Obtaining the accumulated electricity amount corresponding to the accumulated time data; Calculating a difference between the target electric quantity and the accumulated electric quantity; When the obtained difference reaches the error threshold and the accumulated electricity amount is greater than the target electricity amount, the first frequency is reduced to generate the second frequency, and the accumulated time data is reset at the beginning of the next working cycle; When the obtained difference reaches the error threshold and the accumulated electricity amount is less than the target electricity amount, the first frequency is increased to generate the second frequency, and the accumulated time data is reset at the beginning of the next working cycle; When the obtained difference does not reach the error threshold, the first frequency is used as the second frequency.

2. The power regulation method of the electric heater according to claim 1, characterized in that: The method for obtaining the basic frequency corresponding to the power regulation target value is: Based on the power regulation target value corresponding to the target electric heater and the average line voltage of the first power supply, and the single-phase resistance value of the target electric heater, the basic frequency is determined, and the calculation formula is: in: n represents the basic frequency; P represents the power regulation target value; R represents the single-phase resistance value of the target electric heater; U represents the average line voltage of the first power supply; T represents the reference time, which is used to indicate the duration corresponding to a working cycle.

3. The power regulation method of the electric heater according to claim 1 or 2, characterized in that: The method for obtaining the error threshold is: Determine the corresponding power supply average line voltage based on the adjustment determination time to obtain a second power supply average line voltage; A corresponding error threshold is calculated based on the second power supply average line voltage, the single-phase resistance value of the target electric heater, and a preset error parameter.

4. The power regulation method of the electric heater according to claim 1, characterized in that: Divide the reference time according to the number of devices to be controlled to obtain a number of control time points corresponding to the number of devices to be controlled, wherein the number of devices to be controlled represents the number of power regulating devices to be controlled, and the reference time represents the duration corresponding to a working cycle; A power regulating signal is sent to a power regulating device to be controlled at each control time point, and a stop signal is sent to the power regulating device to be controlled according to a first frequency corresponding to the power regulating device to be controlled.

5. A power regulation system for an electric heater, characterized in that: Used to control the operation of a power regulating device corresponding to an electric heater based on the number of switched-on frequencies, comprising: The PLC is connected to an external DCS system signal and is used to receive a power adjustment target value corresponding to the electric heater issued by the external DCS system; A power regulating device corresponding one to one with the electric heater, the power regulating device being connected to the PLC signal; A measuring device corresponding to each of the electric heaters, the measuring device being connected to the PLC signal and used to send voltage data, current data and electricity measurement data of the corresponding molten salt electric heater to the PLC; The PLC is used to execute the power regulation method of the electric heater according to any one of claims 1 to 4.

6. The power regulation system of the electric heater according to claim 5, characterized in that: The power regulating device has an A-phase voltage input terminal, a B-phase voltage input terminal, a C-phase voltage input terminal and a voltage output terminal, and the voltage output terminal is coupled to the corresponding electric heater; The power regulating device also includes a first series branch, a second series branch, a third series branch, a trigger control circuit and an overvoltage protection circuit; One end of the first series branch is coupled to the A-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively; One end of the second series branch is coupled to the B-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively; One end of the third series branch is coupled to the C-phase voltage input terminal, and the other end is coupled to the voltage output terminal and the overvoltage protection circuit respectively; The first series branch and the third series branch are provided with thyristor valve groups; The trigger control circuit is connected to the PLC signal and is also coupled to each thyristor valve group respectively, for receiving the power regulation signal sent by the PLC, and based on the power regulation signal, when the AB line voltage or the BC line voltage passes through zero, controlling the corresponding thyristor valve group to turn on, and when the A phase voltage or the C phase voltage passes through zero, controlling the corresponding thyristor valve group to commutate.

7. The power regulation system of the electric heater according to claim 6, characterized in that: The trigger control circuit in the power regulating device includes a connected bidirectional thyristor trigger and a voltage transformer, and the voltage transformer is used to detect the AB line voltage and the BC line voltage; The measuring device comprises: A first current transformer, a second current transformer, a third current transformer and a collector, wherein the collector is coupled to the first current transformer, the second current transformer, the third current transformer and the voltage transformer respectively, and the collector is also connected to the PLC signal; The first current transformer is used to measure the loop phase current corresponding to the first series branch in the corresponding power regulation device; The second current transformer is used to measure the loop phase current corresponding to the third series branch in the corresponding power regulation device; The third current transformer is used to measure zero-sequence current; The collector is used to send the received voltage data and current data to the PLC, and is also used to calculate the electrical quantity based on the received voltage data and current data, obtain the corresponding unit measurement electrical quantity, and send the unit measurement electrical quantity to the PLC.

8. The power regulation system of the electric heater according to claim 6, characterized in that: The power regulating device also includes a charged display branch corresponding to each series branch one by one; The power-on display branch has an indicator light. One end of the power-on display branch is grounded, and the other end is coupled to the corresponding series branch. When the corresponding series branch is turned on, the indicator light is on.

9. The power regulation system of the electric heater according to claim 6, characterized in that: Each series branch is provided with a vacuum contactor, and the vacuum contactor is connected to the PLC signal; The first series branch and the third series branch are also provided with fast fuses.

10. The power regulation system of the electric heater according to claim 6, characterized in that: The power regulating device also includes a heat dissipation system; The heat dissipation system is connected to the PLC signal.

Images