JPS61141005A - Control system - Google Patents

Abstract

PURPOSE:To prevent a hunting phenomenon and to improve the responsiveness by performing the simultaneous start/stop control within the load variation capacity and also within the variation allowable range of a controlled system and setting the control time interval according to the present operating capacity. CONSTITUTION:The cool/hot water is sent to the air conditioning load from an air conditioning heat source device by plural pumps via a header. The start/ stop of these pumps is controlled by a controller. This controller consists of a processor, CPU, a fixed memory ROM, a variable memory RAM, etc. The maximum simultaneous start/stop capacity is decided in accordance with the load variation allowable capacity of the receiving facilities and the variable allowable range of a controlled system. Then the simultaneous start/stop control is carried out with pumps of capacities less than said maximum capacity. The control time interval is set at the optimum level in response to the present operating capacity.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control method applied to start and stop control of various controlled devices such as motors, pumps, refrigerators, and heaters. It is something.

[Conventional technology]

For example, when starting or stopping multiple water pumps for air conditioners, the inrush may occur depending on the capacity and voltage fluctuation characteristics of the power receiving, substation, distribution, and distribution equipment. In order to suppress the current and keep voltage fluctuations below a certain value, the devices are started or stopped one by one at fixed time intervals. [Problems to be solved by the invention] However, in the conventional method, the power receiving capacity and voltage fluctuation characteristics, etc., are less than the allowable load fluctuation force, and the system cannot be controlled in accordance with the control target system. Even if the disturbance is within the permissible fluctuation range, be sure to start and stop each unit at regular intervals, and it will take a long time to change the operating status of multiple units. However, there is a problem that the response of controlling the air conditioning status is delayed.

Note that this is a similar problem not only in relation to the power receiving and substation equipment, but also in relation to energy sources involved in the operation of various controlled equipment such as boilers and compressors.

[Means for Solving the Problems] The present invention has an object of fundamentally solving the problems of the conventional art, and in order to achieve this object, it is constituted by the following means.

In other words, if the maximum simultaneous start capacity and maximum simultaneous stop capacity of the target equipment are determined according to the load fluctuation tolerance capacity of the energy source involved in the operation of the target equipment and the fluctuation tolerance range of the controlled system, both of the target equipment's current The time intervals for start-up control and stop control are determined individually according to the operating capacity of the equipment, and after each time interval has elapsed, the target equipment is controlled according to the maximum simultaneous start-up capacity and maximum simultaneous stop capacity.

[Effect]

Therefore, the target devices are started and stopped simultaneously within the load fluctuation tolerance capacity of the energy source and within the fluctuation tolerance range of the controlled system, and the time intervals between startup control and shutdown control are determined according to the current operating capacity. is set optimally, and the responsiveness of control via the target equipment is improved while satisfying the relationship between the control target quantity and the control situation change tolerance characteristic and the relationship with hunting prevention in control.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to figures showing examples.

FIG. 2 is an instrumentation diagram of a group of water pumps for air conditioners. Cold and hot water Ws from nine air conditioner heat source devices (not shown in the diagram) via a header H1 is pumped by a plurality of pumps P1 to Pn K. The water is sent to the air conditioning load as water WF via the header H2, and the start and stop of the pumps Ps to Pn are controlled by the control device CNTK.

In addition, the control device CNT sends and receives data to and from a host device (not shown in the diagram) via a transmission path, and performs control calculations in response to received control commands and detection forces from various sensors S. Determine the output control output, Pon7'P1~P
n and various actuators AC.

Figure 3 is an enlarged block diagram of the control device CNT, which mainly includes a processor such as a microprocessor, CPU, interfaces I/Fs to I/F4, fixed memo, ROM,
Variable memory, RAM, oscillator O for clock pulse generation
The SC and the timer TM are arranged around it, and the terminal equipment TE consisting of a display device, a keyboard, etc. is connected via the interface I/F1, and the transmission path is connected via the interface 1/F2 for transmission and reception. is connected, and an actuator is connected to interface I/F3.
A control signal for the pump Pt-zPn is sent from the interface I/F4.

In this case, the processor CPU operates based on clock pulses from the oscillator O8C, and the fixed memory IJ
It performs control while executing instructions in the ROM and accessing predetermined data to the variable memory RAM.
Control timing is determined according to the timing status of the timer TM by counting clock pulses, while control is based on command data from the host device stored in the variable memory RAM, self-management data, detection data from the sensor S, etc. It performs calculations and control decisions, and sends control signals to pumps P1 to Pn and actuator ACK.

Furthermore, the terminal device TE can freely display, input, and update necessary data, making it possible to monitor and change the control status.

Note that the variable memory IJ RAM stores tables to be described later, and these are used for decisions regarding control of the pumps Pt-wPH.

Figure 1 is a flowchart of the control situation by the processor CPU. is the maximum simultaneous starting ability and maximum simultaneous stopping ability, depending on the pumping capacity of pumps pl-pn.

The power is determined and stored in the variable memory IJ RAM, and the ranking table in Table 1 and the situation table in Table 2 shown below are also stored], and these can be used as necessary. It has become something that can be done.

Table 1 Table 2 Note that each capacity of each pump P1 to pm is also individually stored in the variable memory IJRAM.

In Fig. 1, first, the total operating power of each pump currently in operation is determined according to the operating status in Table 2 and the contents of the variable memo IJ RAM, and the current operating capacity of each pump is calculated using the method described later. Find OND/OFD from 1101
, determine the time interval OND for start control and the time interval OFD for stop control, and then, according to the control command data for each pump P1 to P, set the equipment according to the start order shown in Table 1, for example. Store the number in the ranking table#
102, then -pointer・i=1/register÷1−・'C for the pointer that specifies this address and the first register that adds the simultaneous activation capability
5=O'103 respectively %1# and sOy; l-
Set it and OND elapsed since the last startup? ``111'' becomes Y due to the time-up of the timer TM. Is the command to l based on the command data ON? ``112'' determines the command to pump P1 at address i.

According to YK of this, 11 is currently OFF? '#-113'-
Check according to the operating conditions in Table 1, and check if this is Y.
Noto.

If the
ct=ci+ci '114 causes registers φ1°P3 to L, =Ny, -1°□. 1 Yani 1. : After storing the result, check whether the contents of the buffer register have reached the maximum simultaneous activation capacity MAX *'Ct) MAXI?
'115 KjJ), and during this period N (No) F), transfer the contents of the register φ1 to register φ1 to 'C1←Ct' 121, and then store the activation command of 'l in memory 1122. Okay, let's use this monitor as variable memory R.
After storing it in a predetermined area of AM and adding 11# to the pointer by 11=l+l 1123, %i=n? '1
24ON''K, steps 112 and subsequent steps are repeated.

Therefore, according to the command data, ON and dOFF commands are randomly given to each of the pumps Pl to Pn, but the pumps that are commanded to turn on have the maximum simultaneous starting capacity MAX.
Only those with a total capacity of 1 or less are selected according to the first ranking, and the data of the total capacity is stored in a predetermined area of the variable memory RAM by the Makoto step 122, and
OND and OFD are determined according to the current total operating capacity, and if the operating capacity is large, it will take less time for the amount of variation in response to control to stabilize for the same control situation change, and If the capacity is small, it will take a long time until the amount of variation corresponding to the same control is stabilized, so the OND and OFD will be set accordingly.

Next, as in step 102, the device number is stored in the order table according to the 1 stop order (1131), and then as in step 103, the pointer and the second register are set to 1 pointer, 1 work 1''/register◆2, C*=
-Cs ' 132, set the pointer to %l# again, and set the register φ2 to 1. Simultaneous activation and simultaneous stopping cancel each other out disturbances in the controlled system.
After storing the contents of register ◆1 as a negative value, the ant swarm stop command used in emergencies is included in the command data. Ah, 9? '1
41, and according to Y of this, further specify change of maximum simultaneous stopping ability % MAX 2 in the command data.
Determine #142, if this is also Y, 1 specified ability → M
Update pMλX2 by AX2'143 and ignore the elapsed time since the previous command? “Judge 144.

If either of steps 141 or 144 is XN, similarly to steps 111 to 113, %OFD elapsed since the previous stop? 'In response to 1510Y, is the command to 15 by command data OFF? ' While determining 152, is 11 currently ON based on Table 2? ', 153 are judged, and if both are Y, a new stop is performed, and in the same way as steps 114 and 115, go to puff 77 register p'
C4 = Cz-) - CI '154, store the result of adding the capacity CI of the pump Pi to the contents of the register 2, and then check whether the contents of the buffer register have reached the maximum simultaneous stop capacity MAX 2. TurtleCt) MAXz?
'155, and while this is N, %C2←C1
'161 transfers the contents of the buffer register to register ◆2, stores the stop command 11 in the memory in the same way as step 122 (1162j), and adds %i=1+1 I163 to the pointer. conduct, %l=n
? Step 152 and subsequent steps are repeated through N of '164. -For this reason, pumps that are commanded to turn off by the command data and have a total capacity of MAX 2 or less are selected according to the ranking in Table 1,
According to step 162, these data are stored in variable memory.
It is stored in a predetermined area of RAM.

When each of the above steps is completed, 1 output processing 1171 simultaneously sends a start and stop signal to each cylinder to be started and each pump to be stopped according to the contents of a predetermined area via the interface I/F 4. At the same time, the contents of Table 2 are updated according to these conditions.

Therefore, by determining the maximum simultaneous starting capacity and maximum simultaneous stopping capacity according to the load fluctuation tolerance capacity of the power receiving equipment and the fluctuation tolerance range of the controlled system, it is possible to simultaneously The pumps P1 to Pn are started and stopped, and the responsiveness of the air conditioning condition via the pumps P1 to Pn is improved, and the inrush current, voltage fluctuation, and disturbance in the controlled system are suppressed to below permissible values. FIG. 4 is a flowchart similar to FIG. 1 showing another embodiment, in which the maximum simultaneous starting capacity and maximum simultaneous stopping capacity are optimized according to the current operating capacity. If the maximum number of simultaneous start-up units MAX3 and the innermost number of simultaneous stop units MAX4 are used as the capacity, steps 114 and 154 in FIG. 1 are omitted, and steps 101.10
The steps 3, 115, 121, 132, 155, and 161 are replaced by steps 201, 203, 222, 223, 232, 262, and 263, which are the same as in FIG. -1 In other words, counters are used in place of registers φl and φ2 in Fig. 1, and the capacities of each pump P1 to Pn are equal to each other.
Find ND and OFD. After determining the OND and OFD according to '201, set the value using 'pointer, i=1/counter, C=0' and '203,' and then calculate 'C=C.
+I Register the counter by I222, %C= MA
Xa? ' After checking the total number of simultaneous startups using 223, 1 pointer, l=1/counter, C=-
C'233, set the pointer again and
In order to offset the number of simultaneous startups and simultaneous stoppages, set the previous count value to the counter as a negative value, and set the %
After registering the counter with C=C+l#262,'
C=MAX4? According to '263, the number of simultaneous stops is checked.

Therefore, if the maximum simultaneous starting capacity and the maximum number of simultaneous stopping units are determined according to the load fluctuation tolerable capacity of the power receiving substation and one distribution equipment and the fluctuation tolerance range of the controlled quantity, the same effect as in Figure 1 can be obtained. can get.

FIG. 5 shows steps 101 and ? This is a diagram showing specific means of 01, and shows an example of the relationship between the operating capacity Q expressed by the operating capacity or the number of operating units, and OND and OFD, and the values of OND and OFD are fixed. Memory R
After storing it in OM, it can be stored in O
The value of ND or OFD may be read.

-Also, the following formula 〇 operation is performed, and the results obtained by this are also the same.

0ND=Q・Fl ・・・・・・・・・・・・・・・
il+0FD=Q@F2 ・・・・・・・・・・・・
(2) Fl and F2 are functions determined according to conditions.

,The maximum simultaneous start capacity and maximum simultaneous stop capacity are:
It is determined in consideration of the control condition change tolerance characteristics of the air conditioner, and the time intervals OND and OF of start-up and stop control are determined.
For D, it is necessary to consider similar control situation change response characteristics, prevention of backflow of water supply Wir due to sudden decrease in water supply pressure, prevention of hunting in control, etc.

In addition, the operating capacity may be determined from the controlled quantity, and the relationship between the water flow rate F and pressure P is as shown in Fig. 6 depending on the capacity of each pump and the number of operating units m. When operating at 100% capacity, the flow rate F may be detected by a flow meter or the like and used as Q.

Therefore, it is possible to start and stop multiple pumps at the same time within a permissible range, and
The control time interval is optimally set according to the current operating capacity, and prohibiting the next control until a time interval longer than necessary has elapsed.9. Control response via the target equipment. The stability of the control situation is maintained by setting the time intervals according to the operating capacity.

In addition to water supply pumps, refrigerators, heat pumps, heaters, fans, etc. may also be used as target equipment.
Accordingly, as an energy source, in addition to an electric power source, a steam source such as a boiler, or a pressurized air source such as a compressor may be used, and in Figures 1 and 4, the steps are replaced or , omit unnecessary things,
Alternatively, it may be replaced with an equivalent one, and the configurations in FIGS. 2 and 3 may be modified in various ways, such as omitting the Senna S1 actuator AC or using a software configuration of the timer TM, depending on the conditions. It can be freely transformed.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, a plurality of controlled devices can be controlled to start and/or stop at the same time within the load variation tolerance capacity of the energy source and the variation tolerance range of the controlled system. At the same time, the time intervals for start-up and stop control are optimally set according to the current operating capacity, improving the responsiveness of the control situation via the controlled equipment, and improving the control status of one energy source. Since the load fluctuation tolerance capacity is not exceeded and the stability of the control situation is sufficiently maintained, remarkable effects can be obtained in controlling various target devices.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a flowchart of the control situation, Fig. 2 is an instrumentation diagram, Fig. 3 is a block diagram of the control device, and Fig. 4 is a control situation showing another embodiment. Flowchart, Figure 5 shows the relationship between operating capacity and time interval,
FIG. 6 is a diagram showing the relationship between the pressure and the flow rate pumped by the company pump. P1~Pn...Pump (control target equipment), CNT
@...O control device, CPU...processor, ROM
---"Fixed memory, RAM----Variable memory, T
M...-Timer.

Claims (1)

[Claims] In a control device that controls the start and stop of multiple devices to be controlled, the maximum load change capacity of the energy source involved in the operation of the target devices and the allowable range of variation of the controlled system are In addition to determining the simultaneous start capacity and maximum simultaneous stop capacity, the time intervals for start control and stop control are determined individually according to the current operating capacity of the target equipment, and the maximum simultaneous start capacity is determined after each time interval has elapsed. and a control method characterized in that the target equipment is controlled according to a maximum simultaneous stop capacity.