US-12627154-B2 - Power management systems and methods

US12627154B2US 12627154 B2US12627154 B2US 12627154B2US-12627154-B2

Abstract

Various embodiments of the teachings herein include a system comprising: a local supply of renewable power; a storage device with a discharge characteristic; a switch for electrically connecting the storage device to the local supply; and a system controller. The system controller may be configured to: receive from the local supply a signal indicative of available power; read from a memory a time history of past activations of the storage device; estimate a future demand of power based on the time history; estimate a charge of the storage device based on the future demand of power and the discharge characteristic; compare the charge to the future demand of power; and if the charge is larger than the future demand of power by a predetermined margin, electrically connect the local supply of renewable power to the storage device by closing the switch.

Inventors

Conrad Gähler
Ivo Brand

Assignees

SIEMENS SCHWEIZ AG

Dates

Publication Date: 20260512
Application Date: 20230717
Priority Date: 20220719

Claims (11)

1 . A system comprising a local supply of renewable power; a first storage device having a first discharge characteristic; a first switch for electrically connecting the first storage device to the local supply of renewable power; a system controller having a memory in operative communication with the first switch and with the local supply of renewable power, the system controller configured to: receive from the local supply of renewable power a signal indicative of available power; in response to the signal indicative of available power, read from the memory a first time history of past activations of the first storage device; estimate a first future demand of power based on the first time history of past activations; estimate a first charge of the first storage device based on the first future demand of power and the first discharge characteristic; compare the first charge to the first future demand of power; and if the first charge is larger than the first future demand of power by a predetermined margin, electrically connect the local supply of renewable power to the first storage device by closing the first switch; the first storage device comprises a first heat pump; the first heat pump has a first coefficient of performance being a function of a first temperature inside the first storage device; and the system controller is further configured to: read from the memory a first lookup table mapping thermal charges of the first storage device to first temperatures inside the first storage device; use the first lookup table and the first coefficient of performance to produce a first charging curve of the first storage device mapping amounts of power supplied to the first storage device to thermal charges of the first storage device; and estimate the first charge of the first storage device based on the first future demand of power and based on the first discharge characteristic and based on the first charging curve.
2 . The system according to claim 1 , wherein the system controller is further configured to: connect to a weather forecast controller located remotely from the system controller; receive weather forecast data from the weather forecast controller; and estimate the first future demand of power based on the first time history of past activations and based on the weather forecast data.
3 . The system according to claim 1 , further comprising: a connector to a power grid; and a grid switch for electrically connecting the local supply of renewable power to the connector; wherein the system controller is in operative communication with the grid switch and is configured to, if the first charge is less than the sum of the first future demand and the predetermined margin, electrically connect the at least one local supply of renewable power to the power grid by closing the grid switch.
4 . The system according to claim 1 , further comprising a second storage device comprising a first rechargeable battery; and a second discharge characteristic comprises a second self-discharge characteristic of the first rechargeable battery comprising a first group of materials; the system controller is further configured to: change the second discharge characteristic as a function of the first group of materials; and estimate the second charge of the second storage device based on the first future demand of power and the changed second discharge characteristic.
5 . The system according to claim 1 , further comprising: a second storage device having a second discharge characteristic, the second storage device comprising a second rechargeable battery; a second switch for electrically connecting the second storage device to the local supply of renewable power, the system controller in operative communication with the second switch; the system controller further configured to, if the first charge X 1 is less than the sum of the first future demand F 1 and the predetermined margin: read from the memory a second time history of past activations of the second storage device; estimate a second future demand of power based on the second time history of past activations; estimate a second charge of the second storage device based on the second future demand of power and based on the second discharge characteristic; compare the second charge to the second future demand of power; and if the second charge is larger than the second future demand of power by the predetermined margin, electrically connect the at least one local supply of renewable power to the second storage device by closing the second switch.
6 . The system according to claim 5 , wherein: the second discharge characteristic is a second self-discharge characteristic of the second rechargeable battery; the second rechargeable battery comprises a second group of materials; the system controller is further configured to: change the second discharge characteristic as a function of the second group of materials; and estimate the second charge of the second storage device based on the second future demand of power and based on the changed second discharge characteristic.
7 . The system according to claim 4 , further comprising: a second storage device having a second discharge characteristic, the second storage device comprising a second heat pump; a second switch for electrically connecting the second storage device to the local supply of renewable power, the system controller in operative communication with the second switch; the system controller further configured to, if the first charge is less than the sum of the first future demand and the predetermined margin: read from the memory a second time history of past activations of the second storage device; estimate a second future demand of power based on the second time history of past activations; estimate a second charge of the second storage device based on the second future demand of power and based on the second discharge characteristic; compare the second charge to the second future demand of power; and if the second charge is larger than the second future demand of power by the predetermined margin, electrically connect the local supply of renewable power to the second storage device by closing the second switch.
8 . The system according to claim 7 , wherein: the second heat pump has a second coefficient of performance being a function of a second temperature inside the second storage device; and the system controller is further configured to: read from the memory a second lookup table mapping thermal charges of the second storage device to second temperatures inside the second storage device; use the second lookup table and the second coefficient of performance to produce a second charging curve of the second storage device, the second charging curve mapping amounts of power supplied to the second storage device to thermal charges of the second storage device; and estimate the second charge of the second storage device based on the second future demand of power and based on the second discharge characteristic and based on the second charging curve.
9 . The system according to claim 5 , wherein the system controller is further configured to: connect to a weather forecast controller located remotely from the system controller; receive weather forecast data from the weather forecast controller; and estimate the second future demand of power based on the second time history of past activations and based on the weather forecast data.
10 . A method of using power from a local supply of renewable power, the method comprising: receiving from the local supply of renewable power a signal indicative of available power; in response to the signal indicative of available power, reading from a memory a first time history of past activations of a first storage device; estimating a first future demand of power based on the first time history of past activations; estimating a first charge of the first storage device based on the first future demand of power and a first discharge characteristic of the first storage device; comparing the first charge to the first future demand of power; and if the first charge is larger than the first future demand of power by a predetermined margin, producing a first signal and sending the first signal to a first switch, the first signal causing the first switch to electrically connect the local supply of renewable power to the first storage device; wherein the first storage device comprises a first heat pump; the first heat pump has a first coefficient of performance being a function of a first temperature inside the first storage device; and the system controller is further configured to: read from the memory a first lookup table mapping thermal charges of the first storage device to first temperatures inside the first storage device; use the first lookup table and the first coefficient of performance to produce a first charging curve of the first storage device mapping amounts of power supplied to the first storage device to thermal charges of the first storage device; and estimate the first charge of the first storage device based on the first future demand of power and based on the first discharge characteristic and based on the first charging curve.
11 . The method according to claim 10 , further comprising, if the first charge is less than the sum of the first future demand and the predetermined margin: reading from the memory a second time history of past activations of a second storage device; estimating a second future demand of power based on the second time history of past activations; estimating a second charge of the second storage device based on the second future demand of power and based on the second discharge characteristic; comparing the second charge to the second future demand of power; and if the second charge is larger than the second future demand of power by the predetermined margin, producing a second signal and sending the second signal to a second switch, the second signal causing the second switch to electrically connect the local supply of renewable power to the second storage device.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to EP Application No. 22185715.4 filed Jul. 19, 2022, the contents of which are hereby incorporated by reference in their entirety. TECHNICAL FIELD The present disclosure relates to power systems. Various embodiments of the teachings herein include methods and/or systems for optimizing power systems such as rooftop photovoltaic systems including improved use of power from a local supply of renewable energy. BACKGROUND Energy management systems and/or power management systems for buildings can orchestrate supply and demand of power for buildings. More specifically, such systems optimize use of power and minimize carbon dioxide emissions by decoupling supply and demand of power. Also, orchestration of supply and demand by an energy management system or by a power management system can align with the management of a power grid. The system then contributes to improved stability of large-scale power grids. To orchestrate supply and demand of power, energy management systems and/or power management systems control loads within a building as well as any supplies of power. An energy and/or power management system can, for example, control the charging of electric vehicles such that vehicles are charged when the cost of electricity is low. An electric vehicle may be, for example, preferentially charged at times when sufficient active and/or reactive power is available from the power grid. Also, a storage device (2a, 2b) may be charged at times when sufficient active and/or reactive power is available from the power grid. Energy management systems and/or power management systems can also control thermal loads of a site. More specifically, energy management systems and/or power management systems can control cooling and/or heating within a building. Buildings can employ hot-water tanks to store thermal energy such as heat. Likewise, cold-water storage tanks can be employed as buffers for coolants such as water. Also, storage ovens can store thermal energy to be released during the day. An energy and/or power management system can, by way of another example, control the charging of a hot-water tank. An energy and/or power management system can, by way of yet another example, control the charging of a cold-water tank and/or of a chilled-water tank. The building can, by way of non-limiting example, be a commercial and/or an industrial and/or a residential building. Patent application EP2993640A1 deals with a power management system including a building management system having a base load and at least one variable load. At least one variable load of the building comprises a charging point for an electric vehicle. The building management system of EP2993640A1 uses an algorithm to schedule the various loads of a building. The algorithm is employed to arrive at an optimum schedule. The algorithm accommodates various constraints such as a technical constraint of the charging point. The algorithm can, by way of non-limiting example, solve a mixed-integer linear problem. The building management system then controls supply of power to the at least one variable load in accordance the optimum schedule. Another patent application EP3748458A1 deals with a thermal storage device controller working with local sources of renewable power. Local sources of renewable power can, by way of non-limiting example, comprise photovoltaic installations. Rather than feeding power from such sources to a grid, power from local renewable sources is employed to heat a medium inside a local thermal storage tank. A sensor is employed to determine whether the local thermal storage tank can absorb heat. Power from the renewable source is directed to the thermal storage tank in response to a positive determination. In doing so, the system avoids faulted thermal storage tanks due to overheating. According to EP3748458A1, a cooling element inside a thermal storage device can also be activated. Once again, a sensor is employed to check if the thermal storage tank can absorb the thermal energy. SUMMARY The instant disclosure introduces control and/or regulation by an energy and/or power management system in a building having at least one source of renewable power. The at least one source of renewable power may include a photovoltaic installation. The energy and/or power management systems as described herein can rely on forecast data to effectively use energy from a local supply of renewable power. The systems may also schedule activation and/or deactivation of a thermal storage device in accordance with the discharge characteristics of the thermal storage device. In so doing, the system of the instant disclosure also minimizes carbon dioxide footprint and/or contributes to the stability of the power grid. For example, some embodiments of the teachings herein include a system comprising: at least one local supply of renewable power (6a, 6b, 6c), a first storage device (2a) having a first