JP2003086332A - Phase control method improving power factor of electric heater, and heating system of electric eater with improved power factor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the economic loss due to utilization of electric power to the utmost when using a plurality of electric heater. SOLUTION: The power factor of total electric heater is improved by managing N units of electric heaters as a group by a central processing device and a power source control device, and by controlling the load and volume of the alternating current flowing through the electric heaters so that the phase angle of respective electric heater becomes continuous with each other.

Description

Detailed Description of the Invention

The present invention relates to a control method for improving the power factor of an electrothermal heater which can improve the power factor of the entire electrothermal heater when heating is performed by a plurality of electrothermal heaters using an AC power source, and an electrothermal heater. The present invention relates to a heating system with improved heater power factor.

2. Description of the Related Art When an electric heater such as a halogen heater lamp, a nichrome wire heater or a far infrared heater lamp is operated by using an alternating current, these are generally known to have a low power factor. It is desirable to improve the rate and make effective use of electric power. Therefore, in the past,
As a countermeasure, a method has been adopted in which a circuit is provided with a capacitor (referred to as a power factor correction capacitor or a phase advance capacitor) through which an electric current flows with respect to the electric heater. Even when a plurality (N) of these electric heater heaters are provided, each electric heater is individually phase-controlled and heated.

[0002]

However, as described above, the method for individually controlling the phase of each electric heater is as follows.
Although the power factor of each electrothermal heater can be improved, the phase angle is not controlled by associating the phase angle of the entire electrothermal heater. Therefore, as shown in each drawing of FIG. The phase angle is at the same position, and in each electrothermal heater, the ratio of the amount of unused power to the amount of power supplied is large, the efficiency of power usage is poor, and power is wasted.

Under such a background, the inventor of the present invention believes that when a plurality (N) of electric heaters are used, the power factor can be improved by system-controlling the phase angle of each electric heater. Based on the idea, we have earnestly studied. As a result, the present invention has finally been completed.

According to the present invention, which has been completed through the above-mentioned background, the central processing unit controls the alternating current load and the control amount so that the phase angle of each electric heater is continuous.
An object of the present invention is to provide a phase control method for improving the power factor of an electric heating heater capable of suppressing economical loss due to use of electric power as much as possible, and a phase control system for improving the power factor of the electric heating heater.

[0005]

A phase control method for improving the power factor of an electric heater according to claim 1 of the present invention, which is proposed to achieve the above object, comprises a central processing unit and a control power supply unit. Manages a group of N electric heaters by controlling the AC load and the control amount flowing through these electric heaters so that the phase angles between the electric heaters are continuous, thereby improving the power factor of the entire electric heater. It is characterized by The present invention is applied when heating is performed using a plurality of electric heaters. Examples of the electrothermal heater used here include a coil heater, a nichrome heater, a halogen lamp heater, an infrared lamp heater, a far infrared lamp heater, and a sheath heater. The control power supply device according to claim 1 of the present invention is a device that applies a load, a control amount, and a phase angle to each electric heater, and is installed for each electric heater. The number of N is sufficient if it is plural, and the number is not particularly limited. The central processing unit is a unit that, together with each control unit, group-controls the electric heaters and gives a control signal for determining a load and a control amount according to each electric heater to each control power supply unit. Alternatively, it is performed by a control signal according to a control program stored in a storage unit of a personal computer connected to the central processing unit. The control is performed by applying an AC load and a control amount so that the phase angles of the electric heaters are continuous. For example, the timing of applying the voltage may be set as in the following example. (1) If two electric heaters having a power factor of 50% are used, and a load and a control amount corresponding to each are given, and phase control is performed so that the phase angles of the electric heaters are mutually equal, the power factor is 50 The power factor can be improved to 100% by the total of two electric heaters of 100%. (2) In addition, if two electric heaters having a power factor of 30% are used, a load and a control amount corresponding to each are applied, and phase control is performed so that the phase angles of the electric heaters are mutually, 100% by the total of two electric heaters with a rate of 30%
The power factor can be improved. This way,
Conventionally, the power factor was not improved by using a plurality of electric heaters, but in the present invention, it is possible to improve the power factor to the above-mentioned high rate, and each electric heater has a continuous phase angle in the same frequency waveform. Since it operates, it becomes possible to effectively use electric power that has not been used in the past. That is, the power factor can be significantly improved. In these phase controls, a control signal that gives a load and a control amount commensurate with each electric heater and makes the phase angle between the electric heaters continuous is a control program of a microcomputer installed in the central processing unit, Alternatively, it is executed according to a control program in a personal computer connected to the central processing unit.

According to a second aspect of the present invention, there is provided a heating system in which the power factor of an electric heater is improved, wherein N electric heaters, a control power supply device connected to each electric heater, and an AC load flowing in each electric heater. A central processing unit for supplying a signal for controlling the control amount and the phase angle to the control power supply unit to make the phase angle between the electric heaters continuous so as to improve the power factor of the entire electric heater. To do. This claim 2
The heating system according to claim 1 is a system for realizing the method according to claim 1, and when the heating system is constructed, the same power factor improvement as described above can be performed.

A heating system in which the power factor of the electric heater is improved according to a third aspect, in addition to the configuration according to the first aspect, between the central processing unit and each control power source device, or the transmission thereof. In addition, the control power supply circuits are connected by a wireless communication line so that control signals corresponding to N electric heaters can be sent, and the control amount sent to each control power supply device is evaluated. Is characterized by being configured so that it can be performed by the central processing unit. This remote control is performed through a communication line. That is, in claims 1 and 2, the central processing unit and each control power supply device are connected by a wired signal line, but in claim 3,
It can be controlled through a wireless or wired communication line. By doing so, since the electric heater can be remotely controlled, the control can be adjusted and changed from a distant place and the heating data can be managed and stored even when the electric heater is operating. Therefore, the central processing unit may be a dedicated control panel or a control unit equipped with a microcomputer, but may be a personal computer. In the former two cases, a personal computer may be connected to the central processing unit. The advantage of using a PC is
The point is that the control program data can be easily managed and saved, the control program specifications can be changed or rewritten, and the control data can be easily input. In addition, a personal computer can be used together to control and manage other equipment and systems installed with the heating system.

According to a fourth aspect of the present invention, there is provided a phase control method for improving the power factor of an electric heater, wherein a control power supply device connected to each of the N electric heaters controls an AC load and a control amount flowing through each electric heater. The electric power heater is controlled so that the phase angles of the electric heaters are continuous with each other to improve the power factor of the entire electric heater. This method eliminates the central processing unit used in the phase control method according to claim 1,
The control signal can be sent between the control power supply devices, and other than that, it is the same as the method of claim 1. That is, it is possible to sequentially send control signals from the control power supply device of the electric heater to the control power supply devices of the adjacent electric heaters having continuous phase angles. This method is suitable when the number of electric heaters is small, but when the number of electric heaters is large, it is preferable to adopt the method of claim 1.

In the heating system according to a fifth aspect of the present invention, the N electric heaters, the AC loads flowing through the electric heaters, the control amount, and the phase angle are controlled so that the phase angles of the electric heaters are continuous. A control power supply device connected to each electric heater to improve the power factor of the entire electric heater. This heating system is a heating system corresponding to the method of claim 4, and the gist thereof is the same as the case of claim 4, and other than that,
It is similar to the heating system according to claim 2.

According to a sixth aspect of the present invention, there is provided a heating system in which the power factor of the electric heater is improved, wherein the control power source devices are connected to each other by a wireless or wired communication line. It is characterized in that a configuration for adding a control signal according to each electric heater is added in the order of adjacent control power supply devices. This heating system is such that the control in the heating system according to claim 6 can be performed through a wireless or wired communication line, and the gist thereof is the same as in the case of the heating system according to claim 3. Is.

According to a seventh aspect of the present invention, there is provided a heating system in which the power factor of an electric heater is improved, wherein the heating system according to any of the second, third, fifth and sixth aspects is, for example, three-phase or four-phase. It is characterized in that it is configured with the following multi-phase AC circuit.

Each of the heating systems described in claims 2, 3, 5 and 6 described above utilizes a single-phase AC circuit. I used a multi-phase AC circuit such as.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, specific embodiments for carrying out the method and heating system of the present invention will be described in detail with reference to the drawings shown in the accompanying drawings. It should be noted that each of the accompanying drawings is an example shown for easy understanding of the present invention, and the present invention is not limited to only those shown in these drawings.

Both (a) and (b) of FIG. 1 are
It is the block diagram which simplified the heating system which improved the power factor of the electric heater which used two electric heaters. In each of these figures, the heating system shown in (a) uses two electrothermal heaters, a first and a second electrothermal heaters 1a and 1b, and each electrothermal heater 1a and 1b includes each electrothermal heater. The first and second control power supply devices 2a and 2b for providing a load and a control amount according to 1a and 1b to make the phase angles of the electric heaters 1a and 1b mutually continuous are respectively connected to the electric wires 3, 2. 3 are connected, and each control power supply device 2a, 2b
They are connected by electric lines 4 and 4. Then, together with these control power supply devices 2a and 2b, each electric heater 1
The central processing unit 5 that manages a and 1b as a group and gives control signals for determining the weight and control amount of the load according to the electric heaters 1a and 1b to the control power supply devices 2a and 2b is wireless or wired communication. The lines 6 and 6 are connected so that they can communicate freely. The central processing unit 5 is configured to receive an individual control signal or communication signal from an external device such as a personal computer through a wireless or wired communication line 8, 8. In addition to this configuration, each control power supply device 2
Control signals, heating data, etc. may be transmitted from a, 2b to the personal computer through the wireless or wired communication lines 7, 7 and the communication lines 8, 8. On the contrary,
In the heating system shown in (b), the central processing unit is not provided, but its function is provided in each of the control power supply units 2a and 2b.
It is configured to receive individual control communication signals from the personal computer. The control in the heating system shown in (a) is stored in a control program stored in a memory mounted in the central processing unit 5 or in a memory in a personal computer (not shown) connected to the central processing unit 5. Is calculated and executed according to the control program. The control in the heating system shown in (b) is performed by a control program stored in a memory mounted in each control power supply 2a, 2b, or each control power supply 2a, 2b.
It is calculated and executed according to a control program stored in a memory in a personal computer (not shown) connected to 2b.

In the heating system having such a configuration, for example, a control amount of 50% of the amount of electricity within the same frequency waveform is applied to that of the first electric heater and the second electric heater having the same load. When the phase angle of one electrothermal heater is continuous with the phase angle of the other electrothermal heater in the direction in which unused electric power is used, it becomes as shown in each drawing of FIG. FIG. 2A is a frequency waveform diagram showing the load, the control amount, and the phase angle when the power utilization rate of the first electrothermal heater is 50%. In this frequency waveform diagram, as shown in (a), a load and a control amount with a power utilization rate of 50% are applied to the first electrothermal heater. Then, as shown in FIG. 7B, when the electric current reaches 0 ° (radian angle is 0), the second electric heater
The second electric heater is turned on when the temperature reaches ° (same as π),
When the current reaches 90 ° (same, π / 2) and 360 °
A load and a control amount are given so that each of them turns from ON to OFF when (2π). By doing so, as shown in FIG. 7C, the electric power utilization rate is increased to 100% by the total of the first electric heater and the second electric heater. That is, the power factor is improved to 100%. (The conventional heating system remains at 50%.)

On the other hand, for example, a control amount of 30% of the amount of electricity in the same frequency waveform is applied to that of the first electric heater and the second electric heater having the same load, so that one of the electric heaters When the phase angle of is continuous with the phase angle of the other electric heater in the direction in which the unused electric power is used, it becomes as shown in each drawing of FIG. Figure 3
It is a frequency waveform diagram which shows a load, a control amount, and a phase angle in case the utilization rate of the electric power by a 1st electrothermal heater is 30%. In this frequency waveform diagram, in the same manner as the method shown in each diagram of FIG. 2, the power utilization factor of the first electrothermal heater is 30%.
% And a control amount, and the amount of electricity used by the second electric heater is 30%. A load and a control amount are given, and the phase angle of the second electric heater is set to the phase angle of the first electric heater. If they are made continuous, the power utilization rate by the first electric heater and the second electric heater becomes 60%. That is, the power factor is improved to 60%.

Next, a heating system using three electric heaters will be described with reference to FIG. This heating system uses two electrothermal heaters, namely, first, second, and third electrothermal heaters 1a, 1b, 1c, and each electrothermal heater 1a, 1b, 1c has these electrothermal heaters 1a, 1b. ，
A load and a control amount corresponding to each electric heater 1a, 1b, 1c is given to 1c, and the first, second, and third for making the phase angle of each electric heater 1a, 1b, 1c mutually continuous. The control power supply devices 2a, 2b, 2c have their respective electric lines 3, 3,
3 are connected, and each control power supply device 2a, 2b, 2
The electric lines 4, 4 and 4 are connected to each other. Then, the electric heaters 1a, 1b, 1c are group-managed together with the control power supply devices 2a, 2b, 2c, and the electric heaters 1
The central processing unit 5 that gives control signals for determining the weights and control amounts of the loads corresponding to a, 1b, and 1c to the respective control power supply units 2a, 2b, and 2c is the first through the wireless communication lines 6, 6, and 6. It is configured to be connected from the electric heater 2a to the second electric heater 2b and further to the third electric heater 2c. With this configuration, as shown in FIG. 5, for example, when the electric power utilization rate of each electrothermal heater is 30%, the electric power utilization rate of these electrothermal heaters is (3
0%) × 3 = 90%. (The conventional heating system remains at 30%.)

Further, in the present invention, for example, three phases,
A heating system having a four-phase AC circuit can also be used. This is illustrated in FIG. 6, for example. In FIG. 6, the same parts as those in FIGS. 1 and 4 are designated by the same reference numerals, and the duplicated description will be omitted. However, if a three-phase AC circuit is used as shown in FIG. A large number of electric heaters 1a that can use electric power
It is suitable when installing ... 1b ... 1c.

[0019]

As described above, according to the phase control method and the heating system according to the present invention, the load and the heater are the same for each electric heater so that the phase angles are continuous in the same frequency waveform. Each load and control amount are controlled and distributed overall so that the phase angle is continuous in the frequency waveform. As a result, it has become possible to improve the power factor in the direction of using electric power that has not been used until now. Moreover, since these controls can be performed by wireless communication in addition to wired signal lines, remote control can be performed from a position away from the electric heater, and data processing and management via a personal computer can also be performed. It was.

[Brief description of drawings]

FIG. 1A is a block diagram schematically showing a heating system in which the power factor of an electric heater using two electric heaters is improved. FIG. 9B is also another embodiment.

FIG. 2A is a frequency waveform diagram showing a load, a control amount, and a phase angle when the power utilization rate of the first electrothermal heater is 50%. FIG. 6B is a frequency waveform diagram showing the load, the control amount, and the phase angle when the power utilization rate of the second electric heater is 50% in the present embodiment.
FIG. 7C is a frequency waveform diagram showing the use state of electric power when the first and second electric heaters are used in the present embodiment.

FIG. 3 is a frequency waveform diagram showing a total utilization rate when two electric heaters having an electricity utilization rate of 30% are used.

FIG. 4 is a block diagram schematically showing a heating system in which the power factor of an electric heater using three electric heaters is improved.

FIG. 5 is a frequency waveform diagram showing a total utilization power when three electric heaters having a power utilization rate of 30% are used.

[FIG. 6] The power factor of an electric heater using a large number of electric heaters is improved by a three-phase AC circuit.

FIG. 7A is a frequency waveform diagram showing a load, a control amount, and a phase angle at a power utilization rate of 50% by the first electrothermal heater. FIG. 6B is a frequency waveform diagram showing the load, the control amount, and the phase angle when the power utilization rate of the second electrothermal heater is 50% in the related art.
FIG. 6C is a frequency waveform diagram showing the use state of electric power when the first and second electric heaters are used in the conventional technique.

[Explanation of symbols]

1a, 1b, 1c Electric heater 2a, 2b, 2c control power supply device 3 electric wires 4 electric wires 5 Central processing unit 6 communication lines 7 communication lines 8 communication lines 9 communication lines

Claims (7)

[Claims] 1. A central processing unit and a control power supply unit control N electric heaters in groups, and the AC load and control amount flowing through these electric heaters are continuous in phase angle between the electric heaters. Is controlled so as to improve the power factor of the entire electrothermal heater. A phase control method for improving the power factor of an electrothermal heater. 2. N electric heaters, a control power supply device connected to each electric heater, an AC load flowing to each electric heater, a signal for controlling a control amount and a phase angle are given to the control power supply device. A heating system with improved power factor of an electric heater, comprising: a central processing unit for improving the power factor of the entire electric heater by making the phase angle of each electric heater continuous. 3. Between the central processing unit and each control power supply unit,
Alternatively, in addition to these transmissions, the control power supply circuits are connected by a wireless or wired communication line so that a control signal corresponding to N electric heaters can be sent, and each control power supply device The heating system with improved power factor of the electric heater according to claim 2, wherein the central processing unit can evaluate the control amount sent to the heating system. 4. A control power supply device connected to each of the N electric heaters controls the AC load and control amount flowing in each electric heater so that the phase angles of the electric heaters are continuous with each other. A phase control method for improving the power factor of an electric heater, characterized by improving the power factor of the entire electric heater. 5. The N electric heaters, the AC loads flowing through the electric heaters, the control amount, and the phase angle are controlled to make the phase angles of the electric heaters continuous to improve the power factor of the entire electric heater. A heating system with improved power factor of the electrothermal heater, comprising: a control power supply device connected to each electrothermal heater in order to do so. 6. The control power supply devices are connected by a wireless or wired communication line so that control signals corresponding to the respective electric heaters can be sent in the order of adjacent control power supply devices. A heating system in which the power factor of the electric heater according to claim 5 is improved. 7. The heating system according to any one of claims 2, 3, 5 and 6, for example, improves the power factor of a heating device provided with a multi-phase AC circuit including three-phase, four-phase, etc. Let heating system.