Peak Cut Control - Mitsubishi Electric G-50A Technical Manual

9.2.2 Peak cut control

(1) Explanation of function
Connecting the watt-hour meter (PLC) allows conducting the energy saving control of Table 9-2 divided
into 5 levels (Level 0 ~ Level 4) by estimating the power consumption for 30 minutes.
Meantime, the control level is judged with an interval of 1 minute, and the control of higher level is
applied in accordance with the measured power consumption for the past 30 minutes and estimated
value.
[How to obtain the estimated value]
Estimated value (kW) = Power consumption in the past 5 minutes (kWh)
In Figure 9-5 for example, it is assumed that the control at the energy saving level 1 is being conducted
in accordance with [Power consumption for the past 30 minutes].
In this occasion, the estimated value after 30 minutes is calculated from [Power consumption for the
past 5 minutes] by Equation 1, it reaches the region of energy saving level 2. In this case, the energy
saving control set at the energy saving control level 2 will be carried out.
By making the energy saving ineffective temperature difference effective, under the control of Level 0,
when the temperature difference between the set and inlet temperature is exceeding 3°C~9°C (able to
set in a unit of 1°C), It is possible not to allow conducting the energy saving control set at Level 0 in
consideration of comfort.
(The control set at Level 1 ~ Level 4 will be conducted regardless of the temperature difference.)
Power consumption
for past 30 minutes
Power
consumption
for past 5 minutes
10kWh
2kWh
1kWh
Before
5 minutes
By setting the target demand value and [Stopping control for 30 minutes] of the energy saving control
item, the peak cut control can be practiced as an application of the level control above.
(2) Required materials
The materials required for the peak cut control are shown in Table 9-4.
Name (Model name)
PC for centralized control
Integrated software (PAC-TG2000A)
Centralized controller (G-50A)
Peak cut control license
Web monitor license
PLC
Pulse counting software
(PAC-YG11CDA, etc.)
66
× 6 (Power consumption for 30 minutes) × 2 (kWh → kW <30 minutes> converted) ----- 1
Level 2
Level 1
Estimation of mean electric
power for 30 minutes
(demand value)
3kWh
Present
Figure 9-5 Level estimation
Table 9-4 Required materials for peak cut control
Maker
PC/AT convertible unit
Mitsubishi Electric
Mitsubishi Electric
Mitsubishi Electric
Mitsubishi Electric
Mitsubishi Electric
Mitsubishi Electric
Estimated power
120kW
consumption
after 30 minutes
Estimated mean
power consumption
for 30 minutes
30 minutes
Remarks
Confirmed operation of IBM, DELL, Hp Compaq.
For PC spec., refer to Table 6-4.
Use Ver.4.1 or later.
Use Ver.2.5 or later.
Requires for each G-50A.
Requires for each G-50A.
Usable commonly with PLC for measuring instrument
charging.
For detail, refer to Table 8-4.
Use Ver.1.01 or later for peak cut control.
120kW