Electrical measurement and control Maximum demand control systems

Transcription

1 Electrical measurement and control Maximum demand control systems M.6

2 M. 6 Maximum demand control systems M.6 - Maximum demand control systems Introduction 3 Product selection table 5 DH96 CPP Digital unit used to control the 6 CVM R8 CPP Digital unit used to control the 8 CA-4 / MR-3 Units used to control the 10 M6-2

3 Maximum demand control systems M.6 Maximum demand control We can find three items in most corporate electricity bills: }}Consumption of active energy (kw h) }}Power factor consumption (kvar h) }} Power rating, contracted power or Maximum demand. Traditionally, utilities companies have focused their energy saving efforts on the following: }}Reduction of the quantity of kw h consumed }}Improvement the electrical system s Power Factor However, there is a third factor that can be taken into account to reduce the electricity bill: Adequate management of the power needed by a company. The optimum management of contracted power can allow us to: }}Reduce contracted power and adjust the levels of power required }}Prevent Maximum demand penalties (when a maximeter is hired) M.6 Definition The is the power accumulated during a determined period, usually between 8 and 30 minutes. The most common period in most countries is 15 minutes. The power is calculated by the maximeter, which records the greatest value in a month, which is the month billed. Calculation of the There are different ways of calculating the : Fixed Window The energy supply company provides an impulse during each period to synchronise the start of the period. Sliding window There are no synchronisation impulses, so that the last 15 minutes are used (in the case of 15 min periods). The value is updated with the last 15 minutes each second. Time Synchronisation Window This is a variation of the fixed window. The supply company provides the synchronisation impulse at the start of the day, which indicates the start of the first period. During the rest of the day, the synchronisations of each period will be provided by the unit's clock instead of the electrical company. A new impulse will be sent by the company at the end of the day, in order to readjust the unit's clock with the company's clock Thermal demand The thermal demand is calculated by a bimetallic analogue maximeter or the electronic simulation of a bimetallic maximeter M6-3

4 M.6 Maximum demand control systems How can we control the maximum demand? The purpose of power control systems is to ensure that the maximum contracted power limit is not exceeded. has large variations in the maximum demand and low load factors, such as smelting, mining, automotive, textile and paper companies, among others. Loads that can be disconnected: }}Packaging machines }} Grinding machines }} OtherIn general, all machines that do not affect the main production process or which are not essential. In addition, an electrical demand control program is highly recommended in the processes with an operation that Without power control With power control Units used to control the CIRCUTOR, SA offers all units required for the optimum management of energy in your company. The different units measure instantaneous power and automatically calculate the power used that is exceeding the contracted power. Therefore, any load can be quickly and reliably disconnected with built-in relays.in addition, the CVM-R8 CPP and CA-4 units can control different rates and guarantee a more accurate control of your installation, depending on the contracted rate. Operating methods There are 2 ways to prevent exceeding the : Preventive The preventive method is used in companies that do not wish to connect or disconnect loads automatically.the system prevents any value above the contracted power with a system of visual or acoustic signals, so that an operator can manually disconnect determined loads. Predictive The predictive method is the most common and intelligent method.it makes a forecast of the situation at the end of the period and optimises loads, so that the maximum number of loads can be connected, ensuring that the maximum limit programmed is not exceeded.this system is obviously valid for fixed window requests or windows with synchronisation. M6-4

5 Maximum demand control systems M.6 Applications How does it affect your bill? This is a real example, with an excess power consumption that affects the monthly electricity bill: Contracted power: 136 kw Maximeter reading: 253 kw Maximum power allowed no additional charges * : 136 kw x 1.05 = kw Excess power consumption * : 253 kw kw = kw penalty kw * : kw x 2 = kw Total kw billed: kw kw = kw The adequate management of the power consumption would not have exceeded 136 kw and would have been billed instead of as regards the "Power Bill" (71.25 % less). * In other countries, the penalty formula is different and it can be even stricter Product selection table No. of controlled loads Company impulse input Operating systems Operating method Software used Communications Page DH96 CPP 4 Yes Any Preventive or predictive Easy Comm RS-232 or RS-485 (1) 6 CVM-R8 CPP 17 (2) Yes Fixed window Predictive CPP-BT / CPP-CT 128 Yes Window sliding or fixed Preventive or predictive Power C RS (1) Type DH96 CPP-RS (2) With expansion module CVM-R10 M6-5

6 M.6 Maximum demand control systems DH96 CPP Digital unit used to control the Description Features Power supply circuit 230 Vac ( %) Consumption Frequency 4 V A (without card), 7 V A (with card) Hz Measurement circuit Reading accuracy 0.5 % (±1 dig) Resolution 10 bits Overvoltage (permanent / during 10 s) 1.2 U n / 2 U n Overload (permanent / during 10 s) 1.2 I n / 5 I n Measurement margin % No. of conversions per cycle 32 Display Seven 14 mm segments, red Digits 4 Display refresh < 1s Decimal place Programmable Scale excess indicator " " Insulation Between the input, measurement and optional card output Test voltage Impulse test Output relays 3 kv, 50 Hz, 1 min 4 kv (1.2 / 50 ms) 1 simple contact Isolation voltage 750 V contact-contact / V Contact-Coil Thermal current (lth) Maximum operation power Mechanical working life Electrical working life Digital inputs Ambient conditions 5 A 750 V A 2 x 107 operations operations at 5 A and 250 V 2 inputs, potential-free contacts (20 ma-24 Vdc) Storage temperature ºC Operating temperature ºC Build features Box material ABS V0, grey anthracite Degree of protection Box and terminals: IP 20 / Front panel: IP 54 Weight 550 g Standards IEC 1010, IEC 348, IEC 664, VDE 0110, VDE 0435 M6-6

7 Maximum demand control systems M.6 DH96 CPP Digital unit used to control the Software References Communications Type Code - DH96 CPP M60201 RS-485 DH96 CPP-RS M60211 Coding table M 6 X X X X 0 0 X X Code Internal Code Auxiliary power supply Current input Standard (230 V) V ac V ac V ac V dc V dc V dc 9 Standard (.../ 5 A) 0... / 1 A 1 Dimensions Connections M6-7

8 M.6 Maximum demand control systems CVM R8 CPP Digital unit used to control the Description Features Power supply circuit Voltage Single-phase 220 Vac ( %) Frequency Hz Consumption 7 V A Output relay characteristics Number of relays 8 Isolation voltage (Ui) 270 V ac / 125 V dc Thermal current (lth) 3 A AC 11 Ie / Ue 2 A / 250 V ac DC 11 Ie / Ue 2 A / 30 V dc Maximum operation power 750 V Aac, 90 W dc Mechanical working life 2 x 107 operations Electrical working life 2 x 105 operations (at full load) Digital inputs 6 inputs, potential-free contacts (20 ma - 24 Vdc) Analogue inputs 2 inputs Vdc Display 1 x 8 Character alphanumerical display (50 x 15 mm) Ambient conditions Operating temperature ºC Build features Type of box Self-extinguishing plastic module Connection Metallic terminals with "posidriv" screws Adjustable to DIN rails (EN 50022) Fixing (Optional fixing with screws) Cover Lexan Front Degree of protection Embedded relay : IP 41 / Terminals : IP 20 Dimensions 140 x 70 x 110 mm (8 modules) Safety Category II (EN 61010) Standards IEC 255, IEC 348, UNE , IEC 664, VDE 0110, UL 94 M6-8

9 Maximum demand control systems M.6 CVM R8 CPP Digital unit used to control the Operation Dimensions Fixed window The unit is synchronised with the company's maximeter during its operation. To do so, it requires the maximeter's synchronism impulses. When it receives the impulse, it ends the period and starts a new one. Measurement by impulses The measurement of energy consumed during each integration period is calculated with the impulses emitted by a meter with an issuer contact or a different measurement unit with an energy impulse output. References Connections Type CVM R8 CPP Code M60311 M6-9

10 M.6 Maximum demand control systems CA- 4 / MR-3 Units used to control the Description Features }} Quickness of of load connection / disconnection response }} Impulse input to measure the maximum demand being measured by the company's meter (when the supply company allows for its installation). If the supply company does not allow its installation, we can install our own meter with the impulse output for such purposes }} Work with the most common maximum demand systems (sliding window and fixed window) }} With auxiliary power supply PS-24, DC }} Safety times to enter medium voltage lines in the system }} Simulation system, to carry out a test before starting the system and prevent unwanted operations }} Top performance / price, with incredible short-term investment returns CA-4 Power supply circuit 24 V dc (± 25 %) Consumption 500 ma Output relays 4 relays Isolation voltage 1,000 V contact-contact V Contact-Coil Thermal current (lth) Maximum operation power Mechanical working life Electrical working life Digital inputs 3 A 1,500 V A 3 x 107 operations 350 operations / hour (at full load) 4 inputs, potential-free contacts (10 ma - 24 V dc) Ambient conditions Operating temperature ºC Build features Can be coupled to DIN rail Fixing (EN 50022) Cover Lexan Front Safety Category I (EN 61010) Standards EN , EN , EN , EN , EN MR-3 Power supply circuit 24 V dc Consumption 65 ma Output relays 3 relays 10 A / 250 Vac Digital inputs 3 polarised inputs Communications RS-485 Ambient conditions Operating temperature ºC M6-10

11 Maximum demand control systems M.6 CA- 4 / MR-3 Units used to control the Control of loads Control of up to 128 loads or groups of loads. System of priorities, to distinguish the loads with a lower priority and which can be commonly disconnected and the loads with the highest priority that must only be disconnected when needed, in order to avoid exceeding the contracted power. Modular system Modular system adapted to the number of loads in any installation. It only acquires what is needed. It has a modular system that can connect / disconnect loads near the loads them selves to simplify the cabling structure, reduce cabling distances and improve the response time. Optional creation of load groups with the same priority and FIFO or LIFO connection / disconnection sequences. Definition of up to 4 load states: Active, Inactive, Forced active and Forced inactive (for example, in the case of forced inactive, we can carry out the repair of a load with no need to worry about the fact that the said load can be reconnected)it detects when the load is connected or stopped. Software Communications and software included to display the information in a PC and store the connections and disconnections of our power control unit. Optional programming of a contracted power calendar for the next 2 years. Optional programming of contracted power calendars in accordance with the hours of the day, type of day, etc. Firstly, the user defines the basic power control parameters, such as the type of window, period of integration, etc. Likewise, the type of calendar of contracted power or the power ratings we wish to attain will be assigned, as well as the types of dates when the rates used by the electricity company will be applied. The software supports up to 8 types of rate on 8 different dates. Assignment of basic parameters Individual calendars available for loads, not only to start and stop them automatically, but also to guarantee the perfect control of power, knowing the loads in operation prior to said tasks. Assignment of the calendar Assignment of the rate M6-11

12 M.6 Maximum demand control systems CA-4 / MR-3 Units used to control the Secondly, the groups of loads are defined, the disconnection system of the loads of this group is assigned (FIFO or LIFO) and the disconnection order of the group in relation to others is also assigned (if it is the first one or the last one, etc.) We can see that the power disconnection order consumed by each load is displayed at all times, including the total power per group, informing the user whether this is a FIFO or LIFO sequence. These groups are created in accordance with the installation (for ex.: groups of compressors or lights, etc.). Next, the loads corresponding to any MR3 or the same CA4 are assigned to each group. The loads in each group are unlimited. Creation of load groups After creating the groups, the user must simply program the loads with their corresponding power, the relay that controls them and if a specific calendar can be created for each one. For example, we can force the disconnection of the machine during a determined time, with no option to connect it again during said period.this period can even be defined over a two year long period, thanks to the memory capacity of the CA-4. Lists of loads New load Calendar of loads When all parameters have been defined, we can create a simulation to check the correct operation and complete the system's configuration. The load status is clearly defined and the information displayed will vary, depending on the status: When the system has been started, the Power Control Software can be used to check the status of loads in real time, stop them manually or even maintain them permanently stopped, by simply selecting the corresponding software. Real-time monitoring M6-12

13 Maximum demand control systems M.6 CA-4 / MR-3 Units used to control the References Dimensions Description Type Code Load controller + software CA-4 M60411 MR-3 3-line expansion MR-3 M60412 Basic power control kit (3 Loads): 1 CA-4 controller 1 PS-24 Power Supply 24V dc 1 power control software installed in the box (280 x 280 x 150) CPP-B M60421 CA-4 Connections M6-13

14 M.6 Maximum demand control systems M6-14