The present disclosure relates to the field of energy management, and more particularly to a power grid electric transient detector, a method of detecting a power grid electric transient and an electric management system detecting a power grid electric transient.
Demand Side Management (DSM) programs aim at reducing overall energy consumption and/or diminish consumption of utility resources by utility consumers during peak periods. The adoption of DSM initiatives depends mainly on implementation costs and convenience, for both the utility provider and utility consumers.
Current DSM programs and DSM systems are based on predicting aggregated utility consumption (i.e. day-ahead or hours-ahead), scheduled utility network control, and/or utility broadcasting of consumption reduction incentives. These programs target local utility consumption so as to avoid or reduce stress caused by peak periods on the utility resource grid.
Typically, scheduled utility network control and utility consumption reduction incentives require communications between the utility provider and utility consumers. Such DSM programs and systems thus rely on utility network control signals exchanged between the utility resource grid and the utility resource consumers. To provide such exchanges, additional implementation costs are necessary, and the return on the investment for both the utility provider and utility consumers are not always important enough to ensure a broad adoption. Furthermore, such DSM programs eventually affect a comfort level of the utility resource consumer, adding to the resistance to adopt such programs.
There is therefore a need for a method and system for managing utility resources, which is more easily deployable and scalable, while proving interesting for both the utility provider and utility consumers.
According to a first aspect, the present disclosure relates to a power grid electric transient detector comprising an input unit, a digital filter and a processor. The input unit receives an electric parameter of electricity received from a power grid at a consuming facility. The digital filter extracts transients of the electric parameter. The processor analyzes the transients of the electric parameter and generates a power grid performance index based on the analyzed transients of the electric parameter.
According to a second aspect, the present disclosure relates to a method for detecting a power grid electric transient. The method comprises receiving at an input unit an electric parameter for electricity received from an electric grid at a consuming facility. The method also comprises extracting by a digital filter, a transient of the electric parameter. The method further analyzes by a processor, the transient of the electric. The method generates by the processor, a power grid performance index based on the analyzed transient of the electric parameter.
According to a third aspect, the present disclosure relates to an electric management system for managing electric provisioning at a consuming facility. The electric management system comprises a measurement unit, a power grid electric transient detector and an electric provisioning unit. The measurement unit is connected to an electric supply of the consuming facility. The measurement unit measures at least one electric parameter of the electricity received by the consuming facility. The power grid electric transient detector comprises an input unit for receiving the at least one measured electric parameter from the measurement unit. The power grid electric transient detector further comprises a digital filter for extracting a transient of at least one of the electric parameters. The power grid electric transient detector also comprises a processor for analyzing the transient of the at least one of the electric parameters and generating a power grid performance index based on the analyzed transient of the at least one of the electric parameters. The electric provisioning unit comprises an input unit for receiving the power grid performance index. The electric provisioning unit also comprises a processor for analyzing the grid performance index and managing electric provisioning of the consuming facility based on the analyzed grid performance index.
Embodiments of the disclosure will be described by way of example only with reference to the accompanying drawings, in which:
The foregoing and other features will become more apparent upon reading of the following non-restrictive description of illustrative embodiments thereof, given by way of example only with reference to the accompanying drawings. Like numerals represent like features on the various drawings.
Various aspects of the present disclosure generally address the local estimation of a power grid electric transient, and more particularly a power grid electric transient detector, a method for detecting a power grid electric transient, and an electric management comprising such a power grid electric transient detector.
The following terminology is used throughout the present disclosure:
The present specification describes a power grid electric transient detector, which provides local estimation of the power grid electric transient from the consuming facility. The power grid electric transient detector relies on electric parameters that can be measured and/or extracted from the electricity received at the consuming facility and generates therefrom a power grid performance index. The present power grid electric transient detector thus overcomes the communications required between the electric provider managing the power grid and the consuming facility, as transients of the power grid to which the consuming facility is connected to are locally estimated from the behavior of the power grid at the consuming facility. The present specification also provides a method for locally detecting a power grid electric transient, and an electric management system which includes the present power grid electric transient detector.
Power grids provide electricity to many consuming facilities concurrently. As the electric needs of the various consuming facilities increase or reduce, the electricity provided by the power grid is affected by such variations. The effect on the power grid of the increase or reduction of each consuming facility is negligible, but the aggregated increase or reduction results in the presence of transients to one or several electric parameters of the electricity received at each consuming facility.
The present power grid electric transient detector, method and electric management system propose a new solution to the management of electricity at the consuming facilities by detecting the transients present in the one or several electric parameters of the electricity received or consumed. To detect and estimate the transients present in the one or several electric parameters, the present power grid electric transient detector receives measurements of the one or several electric parameters for the electricity received at the consuming facility. Thus, the present power grid electric transient detector, method and electric management system offer a completely scalable and quickly deployable solution, for obtaining a better grasp of the current status of the power grid, and local control of the electricity consumed based on the power grid transient detection obtained locally.
Referring now to
The input unit 110 may continuously receive the one or several electric parameter(s) 112a and 112b, or the input unit 110 may periodically or intermittently receive the one or several electric parameter(s) 112a and 112b, for example depending on the hours of the day, day of the week, holidays, etc. The input unit 110 may receive several electric parameters 112a and 112b concurrently or sequentially for the electricity received at the consuming facility. For example, the input unit 110 may continuously receive one electric parameter 112a and receive another electric parameter 112b intermittently. Alternatively, the input unit 110 may continuously receive the various electric parameters 112a and 112b concurrently. Although only two electric parameters 112a and 112b are shown on
Although not specifically shown, the input unit 110 may further comprise an analog/digital converter, for receiving electric parameters 112a and 112b in an analog format and converting the analog electric parameters into digital electric parameters.
The input unit 110 provides the received electric parameters 112a and 112b to a memory 120 for storage. The memory 120 may store the received electric parameters 112a and 112b as a first-in first-out buffer or any other known storage method. The input unit 110 also provides the received one or several electric parameter(s) 112a and 112b to a digital filter 130. The digital filter 130 extracts transients 132 of each of the one or several of electric parameters 112a and 112b. The extracted transients 132 of electric parameters 112a and 112b are provided to a processor 140. A description of how the digital filter 130 extracts transients from the one or several electric parameters 112a and 112b and examples thereof will be provided further.
The processor 140 may be implemented by a single processor, a plurality of processors, a Field Programmable Gate Array, or performed in the cloud (although not shown). The processor 140 receives the extracted transients 132 either directly from an electric connection to the digital filter 130, or wirelessly, and analyzes the transients 132 and the electric parameters 112a and 112b. The analysis of the transients 132 and the electric parameters 112a and 11b enables the processor to generate a power grid performance index, as described hereinafter.
The digital filter 130 extracts the transients, present on the electricity received and/or consumed. The electric parameter, denoted X(n) is convolved with the digital filter 130, denoted ψ to obtain the transient(s) δ(k) according to equation (1).
where: 2l+1 is a number of coefficients of the digital filter 130;
The digital filter 130, u, can be defined for example using a Ricker wavelet ψR, mathematically represented in equation (2), or using other transversal filters, e.g. Morlet wavelet filter ψM mathematically represented by equation (3) or a Gaussian filter GF mathematically represented by equation (4).
Notice that a, in the formulation of Ricker wavelet ψR of equation (2) corresponds to a first zero crossing of the wavelet function which also corresponds to a position of one standard deviation of the exponential term at right of equation (2).
In the formulation of the Morlet wavelet filter ψM represented mathematically by equation (3), a and b are respectively the dilation and translation coefficients, and the term β is used to control the shape of the wavelet.
If the Gaussian filter mathematically represented by equation (4) is employed, the transient information can be computed using equation (5), which reads as follows:
Reference is now made concurrently to
The processor 140 uses the detected transients 132 and the electric parameter, which in the present example is the measured RMS voltage 112a, to determine the estimated voltage step 133 (up or down), denoted ΔX, introduced by the regulation system of the power grid (e.g. LTCs). The detection procedure is based on the comparison of the instantaneous value of transient information 132, δ, to a detection threshold 136, denoted δTH, defined in terms of the standard deviation (σ) of historic transient information 132.
Considering common continuous probability distribution, the information within −3σ and +3σ of the voltage transients is determined to cover 99.7% of the normal distribution which corresponds to the typical variations and noise of the measured electric parameter for the present example. Therefore, for the sake of the present example, the transients higher than 3σ will be detected, but such a range is determined on a per electrical parameter and per power grid specification basis and should not be construed as a predefined range to be respected. Taking that feature into account, sudden and high transients are identified considering a δTH setting higher than 3σ.
As illustrated in
From the utility RMS voltage 112 (also denoted X) and the estimated accumulated voltage compensation 134 (ΔXC) it is possible for the processor 140 to obtain the estimated uncompensated voltage 135 {circumflex over (X)}(n) using the equation (6).
{circumflex over (X)}(n)=X(n)+ΔXC(n) (6)
The relative power profile of the power grid at the instant n, ,v(n), can be calculated by the processor 140 from the measurement 112 (X) and the estimated voltage (ΔX) 133 (or directly from the estimated accumulated voltage compensation 134 (ΔXc) according to equation (7).
The estimated ,v(n), defined by equation (7), can be computed by the processor 140 with regard to a specific instant m, the default setting applied being m=1 in order to define an analysis with reference to the first data of measurement window. However, for convenience according to the desired period of analysis, m can be set to correspond to any different instant within the recorded dataset.
The estimated relative power ,v(n) is calculated by the processor 140, and is an example of the power grid performance index 142, providing the information of peak and off-peak periods to be used by a management system, discussed further, to generate a curtailment or a modulation signal.
An example of the detection of transient information 132 and the estimated uncompensated voltage 135 is presented in
An example of the estimated relative power 133, for a period of one week and for one day in January 2016, is presented in
Reference is now further made to
This signal ,f(n), can be used as the power grid performance index 142, in the form of an incentive or control signal for energy management purposes. Notice that mean frequency 131 (f) is obtained from the measured frequency 106 by means of the Gaussian digital filter 130.
Reference is now made concurrently to
Reference is now made to
Reference is now made concurrently to
The measurement unit 610 is connected to the electric supply of the consuming facility. Examples of configurations of connection of the measurement unit 610 to the electric supply of the consuming facility 640 are depicted in
The electric parameters 112a and 112b measured by the electric parameter sensors 612 and 614 are provided to the power grid electric transient detector 100 for detecting the power grid electric transients therein, as previously described. The electric provisioning unit 620, in
As previously discussed, the power grid performance index 142 may consist on any of the following: a power grid estimated voltage, a power grid estimated frequency, a power grid estimated incentive message and a power grid estimated control message. Thus, the present power grid electric transient detector 100 thus allows the present electric management unit 600 to manage the provisioning of electricity to the consuming facility 640, while taking into consideration the state of the power grid. The present electric management system 600 further allows management of the provisioning of electricity to the consuming facility 640 while taking concurrently into consideration the status of the power grid 630, but also the particular environmental conditions (exterior temperature, interior temperature, humidity level, lighting, solar lighting, etc.) of the consuming facility 640.
Thus, the present power grid electric transient detector 100, method 500 and electric management system 600 provide an efficient solution, which is easily deployable and scalable, for managing utility resources, while proving interesting for both the utility provider and utility consumers.
Although the present disclosure has been described hereinabove by way of non-restrictive, illustrative embodiments thereof, these embodiments may be modified at will within the scope of the appended claims without departing from the spirit and nature of the present disclosure.