JP2016223395A - Pump motor control method of fluid transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump motor control method of a fluid transfer device capable of generating pulsation of fluid with high responsiveness.SOLUTION: In a cooling system 1 for cooling an electronic circuit 6 generating heat, cooling water is circulated between a radiator 2 and a cooler 3 through pipe conduits 4, 5 by a pump P of a fluid transfer device 10. The pump P changes a flow speed of the cooling water by being driven and controlled by a motor M, and generates pulsation in the cooling water. Here, the motor M implements a stop mode for stopping driving of the motor for a predetermined time, and then transfers to a low speed mode, in switching from a high-speed mode rotating at a high rotational frequency to apply a high flow speed, to the low-speed mode rotating at a low rotational frequency to apply a low flow speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pump motor control method for a fluid transfer device.

  Conventionally, it is known that applying a periodic pulsation to a fluid flowing in a pipe line reduces pressure loss (flow resistance) between the pipe line and the fluid and increases the fluid transfer efficiency. Further, it is known that the fluid with periodic pulsation has good heat conduction efficiency, and the heat exchange rate of the heat exchanger is improved by using the fluid with pulsation added to the heat exchanger. .

  As one method for generating periodic pulsation in the fluid flowing through the pipeline, there is known a method of controlling the discharge amount of the pump, specifically, controlling the number of revolutions of the pump motor that drives the pump. (For example, Patent Documents 1 and 2).

  In Patent Document 1, the first period is the first rotation speed, the second period is the second rotation speed different from the first rotation speed, and the first period and the second rotation speed are different from each other. The pulsation is generated in the fluid by alternately rotating the period and rotating the centrifugal pump. That is, in Patent Document 1, the electric power supplied to the pump motor is alternately switched between a high electric power value and a low electric power value to generate periodic pulsation in the fluid.

  Patent Document 2 discloses a technique for pulsating a fluid by controlling an acceleration period in which the pump motor is rotated to accelerate the fluid and a deceleration period in which the motor is stopped to decelerate the fluid. That is, in Patent Document 2, the pump motor is alternately switched between rotation and stop to generate periodic pulsation in the fluid.

JP 11-315999 A Japanese Patent No. 5105292

  However, in Patent Document 1, in order to generate pulsation, the power supplied to the pump motor is switched between a high power value and a low power value, that is, the motor is alternately switched between a high rotation speed and a low rotation speed. It was. However, when the pump motor is switched from a high rotation speed to a low rotation speed, the flow rate does not decrease to a desired value, and the expected pulsation cannot be obtained.

  In particular, in a pump that pumps fluid using an impeller such as a centrifugal pump, the flow path is not blocked by the impeller and the impeller is rotated by the inertia force of the fluid. Even when decelerated, the change in flow velocity was delayed, and the pulsation response was poor.

  Moreover, in patent document 2, since the drive and stop of a pump motor are driven alternately, the flow velocity can be decelerated rapidly. However, when the pump motor is switched from the stop to the drive, there is a problem that it takes time for the motor to reach the predetermined original rotational speed and it takes time to increase the flow velocity to a desired value. As a result, the expected pulsation could not be obtained.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pump motor control method for a fluid transfer device capable of generating pulsation of fluid with good responsiveness.

  In order to solve the above problems, a motor control method for a fluid moving device controls a pump for pumping fluid in a pipeline, a motor for driving the pump, and a flow rate of fluid pumped in the pipeline by the pump. A motor control unit for controlling the rotation of the motor, and a motor high rotation speed region for driving the motor at a high rotation speed for applying a high speed flow velocity for a predetermined time; and a low speed flow velocity is applied. A pump motor control method for a fluid transfer device that periodically generates a motor low rotation speed region that drives the motor at a low rotation speed for a predetermined time to generate pulsation in a fluid pumped from the pump. When switching from the high motor speed region to the low motor speed region, the motor is stopped for a predetermined time.

  According to this configuration, it is possible to effectively decelerate the fluid to a low speed and accelerate the fluid to a high speed in a short time, and generate a responsive pulsation with respect to the fluid flowing in the pipeline. be able to. As a result, the effect of pulsation of the fluid flowing in the pipe line, particularly the thermal conductivity / heat radiation efficiency, can be increased, and the equipment efficiency of the fluid transfer device can be increased.

  In the above-described configuration, the predetermined time for stopping the driving of the motor is that the rotation speed of the motor ranges from a high rotation speed in the motor high rotation speed area to a low rotation speed in the motor low rotation speed area, or a low rotation speed thereof. It is preferable that it is time until it reaches the vicinity of.

According to this configuration, the flow rate of the fluid can be increased from a low speed to a high speed in a short time.
The said structure WHEREIN: It is preferable that the said pump is a non-volume type pump which has an impeller.

  According to this configuration, the impeller acts as a regenerative brake because the impeller acts to lower the flow velocity with respect to the fluid during the time when the motor is stopped. Therefore, it becomes energy saving.

  According to the present invention, it is possible to generate pulsation of a fluid with good responsiveness.

The schematic system block diagram of the cooling system which cools the electronic circuit which mounts the fluid transfer apparatus in the vehicle with cooling water. Similarly, the figure which shows the change of the rotation speed of the motor in each mode, and the flow velocity of a cooling water.

An embodiment of a fluid transfer device will be described.
FIG. 1 shows a schematic system diagram in which the fluid transfer device is embodied in a cooling system for an electronic circuit mounted on a vehicle.

  In the cooling system 1, the radiator 2 and the cooler 3 are connected by pipes 4 and 5, and the cooling water flows between the radiator 2 and the cooler 3 by the pump P of the fluid transfer device 10 provided in the middle of the pipe 4. It comes to circulate.

  The cooler 3 is made of, for example, an aluminum plate, and a flow path is formed in the aluminum plate. The flow path formed in the aluminum plate has an inlet and an outlet, and the cooling water introduced from the radiator 2 passes through the inlet, is led out from the outlet, and is transferred to the radiator 2 again. The cooler 3 (aluminum plate) cools various electronic circuits (for example, an inverter circuit having a large calorific value) 6 mounted on the vehicle.

  That is, the cooling water cooled by the radiator 2 is transferred to the flow path of the cooler 3 (aluminum plate) via the pipe line 4. The cooling water passing through the flow path formed in the cooler 3 (aluminum plate) cools the heated aluminum plate by exchanging heat with the aluminum plate heated by the heat generated by the electronic circuit 6. . This cools the electronic circuit.

  Then, the cooling water heated by the heat exchange in the cooler 3 is transferred from the cooler 3 to the radiator 2 through the pipe line 5, and heat is exchanged in the radiator 2 to be cooled again. And transferred to the cooler 3.

  Thus, the cooling system 1 for cooling the heat generating electronic circuit 6 is constructed by circulating the cooling water between the radiator 2 and the cooler 3 by the pump P of the fluid transfer device 10.

  The pump P of the fluid transfer device 10 is a non-positive displacement pump having an impeller (not shown), and the cooling water is pumped (transferred) as the impeller rotates. Then, the cooling water circulates between the radiator 2 and the cooler 3 via the pipelines 4 and 5.

  The fluid transfer device 10 includes a pump motor (hereinafter simply referred to as a motor) M that drives the pump P. The rotation axis S of the motor M is drivingly connected to the impeller of the pump P, and the impeller of the pump P is rotated at the same rotational speed as the rotation axis S of the motor M in the embodiment. The motor M is an AC motor and is rotationally driven by electric power supplied from the drive circuit 11. The drive circuit 11 generates electric power to be supplied to the motor M based on a control signal from the control circuit 12 and outputs the electric power to the motor M.

  The control circuit 12 is composed of a microcomputer in the present embodiment, and when the pump P pumps (transfers) the cooling water, the rotation speed N of the pump P (motor M) is generated to generate pulsation in the transferred cooling water. A control signal for controlling is generated and output to the drive circuit 11.

More specifically, in order to generate pulsation in the cooling water, the rotational speed of the motor M (the impeller of the pump P) is obtained by periodically repeating different rotational speeds.
In the present embodiment, after the motor M is driven at a high rotation speed N1 for a predetermined time, the motor M is stopped for a predetermined time, and then the motor M is driven at a low rotation speed N2 lower than the high rotation speed N1. The drive control for driving for a predetermined time is repeated periodically.

  That is, the control circuit 12 has three modes of a high speed mode, a stop mode, and a low speed mode in order to generate pulsation in the cooling water that is transferred by controlling the drive circuit 11. Then, the control circuit 12 switches in the order of the high speed mode, the stop mode, and the low speed mode, and repeats this to output a control signal corresponding to each mode to the drive circuit 11.

(High speed mode)
In the high-speed mode, the control circuit 12 generates a first control signal SG1 for outputting electric power (high electric power w1) supplied to the motor M in order to rotate the motor M to a predetermined high rotation speed N1, and a driving circuit. 11 is a mode for outputting to the terminal 11.

  The high rotational speed N1 of the motor M (pump P) is the rotational speed necessary for setting the flow velocity v of the cooling water to the preset high speed v1, and the pump P is assembled to the cooling system 1. It is a value obtained in advance by tests, experiments, and the like.

  Further, the power value of the high power w1 is a power value supplied to the motor M necessary for rotating the motor M at the high rotational speed N1, and is previously tested in a state where the pump P is assembled to the cooling system 1. This is a value obtained through experiments or the like.

(Stop mode)
The stop mode is a mode in which the control circuit 12 generates a second control signal SG <b> 2 for cutting off the supply of power to the motor M and outputs the second control signal SG <b> 2 to the drive circuit 11.

(Low speed mode)
In the low speed mode, the control circuit 12 outputs a lower power (low power w2) than the high power w1 in the high speed mode supplied to the motor M to rotate the motor M to a predetermined low speed N2. 3 is a mode for generating the control signal SG3 and outputting it to the drive circuit 11.

  The low rotation speed N2 of the motor M (pump P) is a rotation speed necessary for setting the flow velocity v of the cooling water to a preset low speed v2 slower than the high speed v1. This is a value obtained in advance by tests, experiments, etc. in a state in which is assembled.

  Further, the power value of the low power w2 is a power value supplied to the motor M necessary for rotating the motor M at the low rotation speed N2, and is tested in advance in a state where the pump P is assembled to the cooling system 1. This is a value obtained through experiments or the like.

  The control circuit 12 switches in advance from the high speed mode, the stop mode, and the low speed mode, and presets the execution time of each mode when it is repeated. That is, the output time (t1 time) of the first control signal SG1 in the high speed mode, the output time (t2 time) of the second control signal SG2 in the stop mode, and the output time (t3 time) of the third control signal SG3 in the low speed mode are Are set in advance.

  Then, as shown in FIG. 2, each mode is as follows: → first mode (t1 time) → second mode (t2 time) → third mode (t3 time) → first mode (t1 time) → second mode (T2 time) → third mode (t3 time) →... Accordingly, the rotational speed N of the motor M and the flow velocity v of the cooling water are set so as to fluctuate as shown in FIG.

  Here, the time t1 (high-speed mode time) is a time necessary for the motor M to reach the high rotational speed N1 from the state where the motor M rotates at the low rotational speed N2 and to stabilize at the high rotational speed N1. This is the time required for the flow velocity v of the cooling water to stabilize from the low speed v2 to the high speed v1.

The time t1 (high-speed mode time) is a value obtained in advance through tests, experiments, etc. in a state where the pump P is assembled to the cooling system 1.
Further, during the time t2 (stop mode time), after the power supply to the motor M rotating at the high rotation speed N1 is cut off, as shown in FIG. 2, the flow velocity v of the cooling water is slightly lower than the low velocity v2. Time to reach a low speed. The time t2 (stop mode time) is a value obtained in advance by tests, experiments, etc. in a state where the pump P is assembled to the cooling system 1.

  Further, the time t3 (low speed mode time) is a time required to reach the low rotational speed N2 after the stop mode ends and stabilize at the low rotational speed N2, as shown in FIG. This is the time required for the cooling water flow velocity v to stabilize at the low speed v2.

The time t3 (low speed mode time) is a value obtained in advance through tests, experiments, etc. in a state where the pump P is assembled to the cooling system 1.
That is, the control circuit 12 outputs the first control signal SG1 during the high-speed mode at time t1, the second control signal SG2 during the stop mode at time t2, and the third control signal SG3 during the low-speed mode at time t3. Are respectively output to the drive circuit 11.

  In the drive circuit 11, the power supplied to the motor M in response to the first to third control signals SG <b> 1 to SG <b> 3 that is periodically repeated is: → high power w <b> 1 (t <b> 1 time) → power supply stop (t <b> 2 time) ) → Low power w2 (t3 time) → Repeated periodically. As a result, the rotational speed N of the motor M is controlled, and in response to the fluctuation of the rotational speed N of the motor M, as shown in FIG. As a result, periodic pulsation is added to the cooling water circulating in the cooling system 1.

Next, the operation of this embodiment will be described.
Now, when switching from the low speed mode to the high speed mode, the control circuit 12 outputs the first control signal SG1 to the drive circuit 11 and switches the power supplied to the motor M from the low power w2 to the high power w1. As shown in FIG. 2, the rotational speed N of the motor M (pump P) increases from the low rotational speed N2 toward the high rotational speed N1.

Along with this, the flow velocity v of the cooling water accelerates and rises toward the high velocity v1 as shown in FIG.
The control circuit 12 outputs the first control signal SG1 to the drive circuit 11 and continues to supply the high power w1 to the motor M until t1 time (high-speed mode time) elapses after switching to the high-speed mode. And as shown in FIG. 2, the rotation speed N of the motor M (pump P) continues rotating at the high rotation speed N1.

Along with this, the flow velocity v of the cooling water reaches a high speed v1 and stabilizes as shown in FIG.
Subsequently, when the high-speed mode is switched to the stop mode, the control circuit 12 outputs the second control signal SG2 to the drive circuit 11 and cuts off the power supply to the motor M. As a result, as shown in FIG. 2, the rotational speed N of the motor M is suddenly decelerated from the high rotational speed N1 toward zero. Along with this, the flow velocity v of the cooling water also rapidly decelerates toward zero as shown in FIG.

  And until t2 time (stop mode time) passes, the control circuit 12 outputs the 2nd control signal SG2 to the drive circuit 11, and continues interrupting | blocking the electric power supply to the motor M. Therefore, as shown in FIG. 2, the motor M continues to stop rotating. Accordingly, the flow velocity v of the cooling water continues to decelerate toward zero as shown in FIG.

  When switching from the stop mode to the low speed mode, that is, when the cooling water flow velocity v decreases to a flow velocity slightly lower than the low speed v2 as shown in FIG. 2, the control circuit 12 outputs the third control signal SG3 to the drive circuit 11. Thus, the low power w2 is supplied to the motor M whose power supply has been cut off. As a result, as shown in FIG. 2, the rotation speed N of the motor M that has stopped rotating increases toward the low rotation speed N2.

At this time, the flow velocity v of the cooling water is at a position slightly lower than the low speed v2 as shown in FIG. 2, and therefore smoothly transitions to the low speed v2.
The control circuit 12 continues to supply the low power w2 to the motor M by outputting the third control signal SG3 to the drive circuit 11 until t3 time (low speed mode time) elapses after switching to the low speed mode. As a result, as shown in FIG. 2, the motor M continues to rotate at a low rotational speed N2. Accordingly, the flow velocity v of the cooling water continues to maintain the low speed v2 until the high speed mode is switched as shown in FIG.

  Thus, as shown in FIG. 2, the flow velocity v of the cooling water transferred by the pump P (impeller) that rotates in conjunction with the motor M varies based on the variation of the rotational speed N in each mode. Thus, pulsation can be generated in the cooling water.

  Then, a stop mode is provided between the high speed mode and the low speed mode, the power supply to the motor M that has supplied the high power w1 is temporarily cut off, and the rotational speed N of the motor M is rapidly decelerated from the high rotational speed N1. I did it. Therefore, the cooling water flow velocity v can be reduced in a short time.

  Further, when the motor M whose power supply has been cut off reaches a speed at which the flow velocity v of the cooling water is slightly lower than the low speed v2, the motor M is supplied with the low power w2, and from that state the motor M is supplied with high power. The high-speed mode for supplying w1 is switched. Therefore, the flow rate v of the cooling water reaches the high speed v1 in a short time.

  From the above, it is possible to generate pulsations with good response to the cooling water flowing through the pipe lines 4 and 5. As a result, the heat exchange efficiency between the cooling water and the radiator 2 and the cooler 3 can be improved, and the pressure loss (flow resistance) between the pipes 4 and 5 and the cooling water can be reduced and the transfer efficiency can be improved. .

Next, the effect of the said embodiment is described below.
(1) According to the present embodiment, a stop mode is provided between the high speed mode and the low speed mode, the power supply to the motor M is temporarily interrupted, and the rotational speed N of the motor M is rapidly decelerated from the high rotational speed N1. Therefore, the flow velocity v of the cooling water can be rapidly reduced without losing the inertial force of the cooling water. Therefore, the flow velocity v can be lowered in a short time.

  (2) According to the present embodiment, the stop mode ends when the cooling water flow velocity v reaches a speed that is slightly lower than the low speed v2, and is switched to the low speed mode. When the low speed mode is switched to the next high speed mode, the flow velocity v is immediately accelerated from the low speed v2 toward the high speed v1. Therefore, the fall of the flow velocity v from the high speed v1 to the low speed v2 can be shortened, and the rise of the flow velocity v from the low speed v2 to the high speed v1 can be shortened. In addition, the load on the motor M can be reduced.

  (3) According to the present embodiment, the cooling water can be cooled in a short time since the flow velocity v can be lowered from the high velocity v1 to the low velocity v2 and the flow velocity v can be raised from the low velocity v2 to the high velocity v1. It is possible to generate pulsations with good response.

The above embodiment may be modified as follows.
In the above embodiment, the supply of electric power to the motor M is interrupted in the stop mode, but the circuit may be configured so that a regenerative brake is applied to the motor M simultaneously with the interruption. Thus, if the regenerative energy obtained by the regenerative brake is charged in the battery mounted on the vehicle, it can contribute to energy saving.

  In the above embodiment, the stop mode is terminated when the cooling water flow velocity v reaches a speed that is slightly slower than the low speed v2. You may implement this so that it may be complete | finished when the flow velocity v of cooling water reaches the low speed v2, or when reaching to the high speed just before the low speed v2.

  In the above embodiment, the fluid transfer device 10 is embodied in the cooling system 1 that circulates the cooling water between the radiator 2 and the cooler 3 via the pipelines 4 and 5. This may be embodied in a transfer system that transfers the fluid in one direction from the transfer source to the other transfer destination.

In the above embodiment, the fluid transfer device 10 transferred the cooling water. You may apply this to the fluid transfer apparatus which transfers other liquid, gas, etc. as a fluid.
In the above embodiment, the pump P is a non-displacement pump having an impeller, but may be applied to a fluid transfer device using other non-displacement pumps.

  DESCRIPTION OF SYMBOLS 1 ... Cooling system, 2 ... Radiator, 3 ... Cooler, 4, 5 ... Pipe line, 6 ... Electronic circuit, 10 ... Fluid transfer device, 11 ... Drive circuit, 12 ... Control circuit, P ... Pump, M ... Motor, N: rotational speed, S: rotating shaft, N1: high rotational speed, N2: low rotational speed, SG1 to SG3: first to third control signals, w1: high power, w2: low power, t1: high speed mode time, t2: Stop mode time, t3: Low speed mode time.

Claims (3)

A pump for pumping fluid in the pipeline;
A motor for driving the pump;
A motor control unit for controlling the rotation of the motor to control the flow rate of the fluid pumped through the pipeline by the pump;
A motor high rotation speed region that drives the motor at a high rotation speed that gives a high speed flow rate for a predetermined time period, and a motor low rotation speed that drives the motor at a predetermined rotation time at a low rotation speed that gives a low speed flow speed. A pump motor control method for a fluid transfer device that periodically generates several regions and generates pulsation in fluid pumped from the pump,
A method for controlling a pump motor of a fluid transfer apparatus, wherein the motor is stopped for a predetermined time when switching from the high motor speed region to the low motor speed region. In the pump motor control method of the fluid transfer device according to claim 1,
The predetermined time for stopping the driving of the motor is such that the rotational speed of the motor reaches from the high rotational speed in the motor high rotational speed area to the low rotational speed in the motor low rotational speed area or in the vicinity of the low rotational speed. A method for controlling a pump motor of a fluid transfer device, characterized in that it is a time until completion. In the pump motor control method of the fluid transfer device according to claim 1 or 2,
A pump motor control method for a fluid transfer device, wherein the pump is a non-positive displacement pump having an impeller.