JPS62290387A - Power controller - Google Patents

Abstract

PURPOSE:To operate a motor in the maximum efficiency and to economize in power, by detecting load torque and feeding the current with the voltage corresponding to the load torque. CONSTITUTION:A load torque detection circuit detects load torque. By the phase control of a TRIAC AO corresponding to the output of the load torque detection circuit, the voltage is given to an induction motor in proportion to torque fluctuations on the load side. On this account, the surplus power is removed and the power can be economized, so that the loss, e.g. heat generation, of a motor can be reduced and the endurability improved.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention "Field of Industrial Application" This invention is an induction motor circuit equipped with a phase control circuit in the power supply system for the purpose of power saving, etc., by removing excess power and saving power. The present invention relates to a power controller that is capable of achieving the following, and also reduces losses such as heat generation of a motor and improves durability.

``Conventional Technology'' In the past, induction motors for home or commercial use were applied with a voltage much higher than the voltage required by the load during normal operation, as a countermeasure against starting or load fluctuations. As a result, the motor is constantly operating at overvoltage, resulting in heat generation and other losses, resulting in large losses.

``Problems to be Solved by the Invention'' In the above-mentioned prior art, since the supply voltage is constant, it has not been possible to remove the loss due to overvoltage, and rather it has been thought that it is a natural problem.

Therefore, as a result of extensive research into eliminating this loss, we found a clue to the solution in the load torque of the motor, resulting in the present invention. In other words, the present invention uses a well-known motor load torque detection method to detect the load torque in analog or digital form and set the power supply voltage to a preset value commensurate with the load torque.
This eliminates the overvoltage state of the motor and reduces loss such as heat generation, thereby achieving efficient operation.

"Embodiments" Examples of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a first embodiment of the present invention. In this embodiment, an analog signal from a load torque detection circuit is transmitted to a trigger circuit for phase control to control voltage for phase control. FIG. 2 is an example of the phase control circuit shown in FIG. 1.

The load torque signal detected as an analog signal is transmitted to the base of transistor 21 of the phase control trigger circuit shown in Figure 2 to control the current between the collector and emitter, and the trigger capacitor of CI reaches the breakover voltage of trigger element 22. The voltage is controlled by adjusting the time.

FIG. 3 is a block diagram of a second embodiment of the present invention. In this embodiment, an analog signal from a load torque detection circuit is digitized by a digital conversion circuit to provide digital voltage control.

FIG. 4 is an example of the phase control circuit shown in FIG. 3. In order to convert the digitized signal into a phase control circuit that generates a voltage according to the signal level, a thyristor trigger circuit is used to conduct one of RIR2R3, which is a resistor adjusted to generate a predetermined voltage. ^IA2
The required voltage is generated by continuously applying a trigger signal to any one of ^3. In other words, all phase-based @adjustment circuits other than those of the embodiments are capable of i+J as long as they are compatible with digital and analog applications. For power supplies, both single-phase and three-phase AC are possible; for three-phase systems, if the phase control circuit shown in Figure 5 or 6 is installed for every 6 phases as shown in Figures 7 and 8, single-phase AC power can be obtained. The same effect can be obtained. In the three-phase system, the current from the load side is allowed to pass without being controlled, and the current from the load side is switched by diodes Z3Z4 to avoid double control. In this case, the conduction is carried out at almost the entire phase angle.

The number of series circuits of resistors and thyristors in the voltage regulating circuits of FIGS. 4 and 6 can be increased as needed.

"Effects of the Invention" As explained above, according to the present invention, it is possible to supply a voltage according to torque fluctuations on the load side, making it possible to significantly save power and improve the durability of the motor.

[Brief explanation of the drawing]

FIG. 1 shows a first embodiment of the present invention, and FIG. 2 shows one embodiment of the phase control adjustment circuit of the first embodiment. FIG. 3 shows a second embodiment of the present invention, and FIG. 4 shows an embodiment of the phase control adjustment circuit of the second embodiment. FIG. 5 shows one embodiment of a phase control adjustment circuit compatible with analog in a three-phase circuit. FIG. 6 shows one embodiment of a digitally compatible phase control adjustment circuit in a three-phase circuit. Figures 7 and 8 are block diagrams of examples of three-phase 1''u source circuits. AO... Thyristor (triac) Z2...
...Trigger element (BSB and diac) CI...
...Trigger capacitor AlΔ2A3...
Thyristor Z1...Transistor RI R2R3...Voltage adjustment resistor Z3Z4...
... Diode patent applicant SP Planning Co., Ltd. Drawing Purification Day) 8 P. 71] Amendment to Procedures for Collapse No. 1 June 25, 1985

Claims (3)

[Claims] (1) The induction motor is operated at maximum efficiency by detecting the load torque of the induction motor and supplying a voltage that can draw out the motor torque that matches the load torque.
A power controller that can save power as a result. (2) A power controller using phase control as the power control method. (3) A power controller using phase control that allows the above-mentioned power control to be compatible with digital and analog.